Fisheries Research Papers - Academia.edu (original) (raw)

Environmental conditions can influence the physiology of marine organisms and have important implications for their reproductive performance and capacity to supply new recruits. This study examined the seasonal reproductive patterns of... more

Environmental conditions can influence the physiology of marine organisms and have important implications for their reproductive performance and capacity to supply new recruits. This study examined the seasonal reproductive patterns of the coral Montipora capitata in habitats exposed to different sedimentation regimes. Although M. capitata is a main reef-building coral in the Hawaiian Archipelago, little is known about the gametogenic cycle and reproductive ecology of this important species. Our results indicate that gamete production in M. capitata is a resilient process; no differences in gamete development or fecundity were observed among sites with very different sedimentation regimes. The gametogenic cycle of M. capitata lasts between 10 and 11 months, with spawning occurring over 3-5 months during warmer months (May-September). Oocytes were found throughout the year, but spermatocysts were only found April-August. The largest increases in oocyte size occurred during February to May, the months when solar radiation increased rapidly. The largest variation in oocyte sizes was found during July and August; during this period individual colonies contained mature oocytes for immediate spawning and new oocytes being formed for spawning the next year. The capacity of M. capitata to reproduce in areas with high sedimentation is an interesting finding highlighting the potential of the species for acclimatization, adaptation, or both. Despite this optimistic finding, the management of terrestrial runoff and the restoration of habitat quality for corals remains a top priority to ensure the renewal and maintenance of coral populations.

Dependence on a vast shared resource built up the economies of herring towns around the north-central and northeastern Atlantic during the first half of the 20th century. During the postwar years, culminating in the early-1960s spike, the... more

Dependence on a vast shared resource built up the economies of herring towns around the north-central and northeastern Atlantic during the first half of the 20th century. During the postwar years, culminating in the early-1960s spike, the fishery rapidly drew down its resource. This killer spike disastrously coincided with an adverse climatic event, collapsing the fishery in the late 1960s. That pattern, of collapse resulting from climatic variation on top of overfishing, has characterized other fisheries crises (for example see Hamilton et al., 2004b). The fisheries events reflect a more general proposition: climate changes tend to impact human affairs largely through interactions with resource use and distribution behaviour, which can reduce or exacerbate climate impacts. We should not expect to see simple, physical impacts from climate alone, unmitigated by social factors.

We describe the finding of a novel viral haemorrhagic septicaemia virus (VHSV) Genotype III strain that caused disease of both a neurological and septicaemic nature in seawater-farmed rainbow trout Oncorhynchus mykiss in Storfjorden,... more

We describe the finding of a novel viral haemorrhagic septicaemia virus (VHSV) Genotype III strain that caused disease of both a neurological and septicaemic nature in seawater-farmed rainbow trout Oncorhynchus mykiss in Storfjorden, Norway. In November 2007, an outbreak of VHS associated with slightly elevated mortality was confirmed at a seawater site rearing rainbow trout (90 to 440 g). Within 3 to 4 mo, the disease was recognised in 3 neighbouring sea sites with ongrowing rainbow trout. The clinical, gross pathological and histopathological findings were in accordance with VHS, and the diagnosis was confirmed by the detection of VHSV in brain and internal tissues by immunohistochemistry, cell culture and reverse transcriptase PCR (RT-PCR). Sequence analysis of the G-gene revealed that the isolated virus clustered with VHSV Genotype III and that the Norwegian isolate represents a unique strain of VHSV. The pathogenicity of the virus strain to rainbow trout and Atlantic salmon Salmo salar was examined using infection experiments. In immersion trials, the Norwegian isolate produced a cumulative mortality of 70% in rainbow trout, while nearly 100% mortality was obtained after intraperitoneal injection of the virus. For Atlantic salmon, no mortality was observed in immersion trials, whereas 52% mortality was observed after intraperitoneal injection. The Norwegian isolate thus represents the first VHSV of Genotype III pathogenic to rainbow trout.

The golden cownose ray, Rhinoptera steindachneri, was one of the most abundant species landed in artisanal elasmobranch fisheries in the northern Gulf of California (Baja California and Sonora) and Bahía Almejas, Mexico during 1998-1999.... more

The golden cownose ray, Rhinoptera steindachneri, was one of the most abundant species landed in artisanal elasmobranch fisheries in the northern Gulf of California (Baja California and Sonora) and Bahía Almejas, Mexico during 1998-1999. In the northern Gulf of California, R. steindachneri was most frequently observed during summer months (11.4% of elasmobranch landings, catch per unit effort (CPUE) = 6.8 individuals/vessel trip) and was rare during winter (0.1%, CPUE = 0.1). In Bahía Almejas, its relative abundance was greater during August (5.2%) than June (0.3%), a trend also evident in CPUE (August = 1.2, June = 0.1). The mean size of R. steindachneri landed in the Gulf of California was 64.3 ± 12.8 (SD) cm disc width (DW). Median size at maturity for Gulf of California specimens was similar for females (70.2 cm DW) and males (69.9 cm DW). Fecundity was found to be one offspring per female, with parturition estimated to occur from late June-August. Size at birth was estimated at 38-45 cm DW after a gestation period of approximately 11-12 months. Greater maximum sizes (to 104 cm DW) and embryo sizes (to 43 cm DW) were observed in Bahía Almejas. The large size at maturity, low fecundity, and long gestation period determined for R. steindachneri indicate that this species could be particularly susceptible to overexploitation.

This paper reviews recent literature on the effects of tariff liberalization on wild caught fish product production structures, development outcomes, and fish stocks. Using the case of canned tuna, the report shows that tariff regimes... more

This paper reviews recent literature on the effects of tariff liberalization on wild caught fish product production structures, development outcomes, and fish stocks. Using the case of canned tuna, the report shows that tariff regimes clearly influence the location of production and processing activities, thereby shaping the international division of labour. While trade measures clearly have significant implications for developing countries, the report finds that the impact of trade preferences and tariff liberalization cannot be adequately understood without taking into consideration the particular characteristics and circumstances of individual countries. Therefore, one-size-fits-all policy prescriptions based on generalized assumptions about the functioning of the world economy will not provide an adequate policy framework. The author puts forward several recommendations concerning measures that could be taken to help developing countries adapt to changes in competitiveness in the evolving trade environment.

issues signals a clear warning for the future sustainability of this global industry. The linking together of global experts in the culture, capture and trading of crustaceans with pathologists, epidemiologists, ecologists, therapeutics... more

issues signals a clear warning for the future sustainability of this global industry. The linking together of global experts in the culture, capture and trading of crustaceans with pathologists, epidemiologists, ecologists, therapeutics specialists and policy makers in the field of food security will allow these issues to be better identified and addressed.

This dissertation examines multiple scales of Indigenous history on the Northwest Coast from the disciplinary perspective of archaeology. I focus on cultural lifeways archaeologically represented in two key domains of human existence:... more

This dissertation examines multiple scales of Indigenous history on the Northwest Coast from the disciplinary perspective of archaeology. I focus on cultural lifeways archaeologically represented in two key domains of human existence: food and settlement. The dissertation consists of six individual case studies that demonstrate the utility of applying multiple spatial and temporal scales to refine archaeological understanding of cultural and historical variability on the Northwest Coast over the Mid-to-Late Holocene (ca. 5,000-200 BP). The first of three regionally scaled analyses presents a coast-wide examination of fisheries data indicating that Pacific herring (Clupea pallasii) exhibit a pervasive and previously under-recognized importance in Northwest Coast Indigenous subsistence practices. Next, I use zooarchaeological data from the southern British Columbia coast to identify a pattern of regional coherence in Coast Salish and Nuu-chah-nulth hunting traditions reflecting the scale of intergenerational cultural practice. The third study re-calibrates the settlement history of a small and historically significant locality in Coast Tsimshian territory (Prince Rupert Harbour) to clarify the temporal resolution of existing radiocarbon datasets and test inferences about social and political change. Following this regional exploration of scale, I document site-specific temporal variability in archaeological fisheries data from a Nuu-chah-nulth ‘big-house’ reflecting climatic and socio-economic change. I examine Indigenous oral histories and archaeological datasets to evaluate these parallel records of settlement in the neighbouring territory of an autonomous Nuu-chah-nulth polity before and during the occupation of a large defensive fortress. Finally, I demonstrate how everyday foodways are archaeologically expressed and reflect ecological differences and active management strategies within several spatially associated sites over millennial timescales. These linked case studies offer new clarity into long-standing debates concerning archaeologically relevant scales of cultural-historical variability on the NWC. They collectively demonstrate an enduring regional and temporal coherence for key aspects of Indigenous resource use and settlement and a historical dynamism at finer scales. I argue this has cultural, historical, and archaeological significance as well as relevance for contemporary understandings of the Northwest Coast environment. I conclude that a focus on the pervasive aspects of the everyday over millennia offers insight into individual actions across broader patterns of history.

Palawan produced 70 percent of the Philippines’ LRFT export. The municipality wanted to maintain or save its LRF and bay fisheries, thus the objectives of this study are to gather information on the status of CPUE and LRF in Taytay Bay,... more

Palawan produced 70 percent of the Philippines’ LRFT export. The municipality wanted to
maintain or save its LRF and bay fisheries, thus the objectives of this study are to gather information on
the status of CPUE and LRF in Taytay Bay, and to provide recommendations to fisheries planning and
management. Standard catch survey method was used to estimate CPUE of different gears. Survey was
conducted every day between August and September 2009, representing the mid-Southwest Monsoon
fishing season. Nine fishing gears operating in the bay were recorded. Drift gillnet has the highest effort
and fish biomass landed, followed by Hookah-spear gun. Bagnet has the highest CPUE followed by
Bottom gillnet, and were most efficient gears in terms of catch/fisher/hour. However, Bagnet CPUE
tended to decrease through the years. Hook and line fisher composed more than half of the fisher’s
population of the bay and was the priority livelihood. The total fishing effort would soon put pressure to
the LRF resources. It will also likely create an unequal distribution of type of fishers in the bay, which will
make bay fisheries unstable. The total catch in the bay per month during Southwest Monsoon period was
estimated to be 337.2 t. Serranidae consisted only 5% of the total catch. Of this, 40% were
Plectropomus leopardus, and the rest were composed of third class serranids and tiger groupers. Of the
serranid species caught, 13% were sold alive, while the rest were sold fresh. The low catch and smaller
sized live fish species indicate that LRF is under pressure and may not be viable anymore. This is
alarming since so many fishermen were competing to catch the same depleting resource, which can
eventually collapse if no immediate management schemes will be introduced. Highlights of
recommendations are: bag net should not operate in the municipal waters, bottom gill net should be
continuously promoted in the bay; status of red grouper stock/population should be monitored, and
immediate regulatory management schemes must be in placed; community-based aquaculture of high
demand-high priced species, with complete breeding and grow-out technology like Cromileptes altivelis
must be introduced to lessen the pressure on existing LRF species; the government should find means to
let fishers indulge in more diverse fisheries to have a stable fishing industry; and another survey must be
conducted during the Northeast Monsoon period.
Key Words: catch per unit effort, Taytay Bay, Sulu Sea, live fish trade.

Small-scale fisheries provide over half the world's wild-caught seafood, employ over 99% of its fishers, and are frequently promoted as a sustainable alternative to large-scale industrial fisheries. However, few studies have... more

Small-scale fisheries provide over half the world's wild-caught seafood, employ over 99% of its fishers, and are frequently promoted as a sustainable alternative to large-scale industrial fisheries. However, few studies have quantitatively examined how possible habitat impacts and non-target species composition vary across gears used in small-scale fisheries, as data are sparse and conservation efforts are largely focused on more iconic species. Here, we quantify and compare the ecosystem impacts of four fishing gears (lobster traps, fish traps, set gillnets, drift gillnets) used in small-scale fisheries of Baja California, Mexico, using at-sea observations and field experiments. Set gillnets had the highest overall impact on both non-target species and habitat, with discard rates higher than most industrial fisheries (34.3% by weight), and an estimated 19.2% of Eisenia arborea kelp and 16.8% of gorgonian corals damaged or removed within 1 m of the net path. Fish traps had the lowest discard rates (0.11%) while lobster traps and drift gillnets had intermediate discard rates (15.1% and 18.5% respectively). In contrast with gillnets, traps caused minimal immediate damage to gorgonian corals and rarely interacted with kelp. Results indicate that ecological impacts depend more on fishing gear type and habitat characteristics than the size of fishing vessels, calling into question broad generalizations that small-scale fisheries are inherently more sustainable than industrial fisheries. Our findings highlight the ecological impacts of artisanal gillnet fisheries as priorities for research, management, and conservation efforts in Baja California and other coastal areas.

We use six decades of catch-at-age data for perch (Perca fluviatilis) and pike (Esox lucius) in Windermere (UK) to estimate age-and sex-specific population sizes, natural mortalities and catchabilities in both species. Population sizes... more

We use six decades of catch-at-age data for perch (Perca fluviatilis) and pike (Esox lucius) in Windermere (UK) to estimate age-and sex-specific population sizes, natural mortalities and catchabilities in both species. Population sizes are estimated by fitting age structured population models to the catch-at-age data using standard maximum likelihood methods. We validate our methods using data simulations, and use our estimates of vital rates (natural mortality, recruitment and catahability) to address important aspects of fisheries biology. ...

The environmental processes associated with the climatic oscillations that drive variability in swordfish catch rates are largely unexplored. This study used generalized additive models fitted to longline fishery data to investigate... more

The environmental processes associated with the climatic oscillations that drive variability in swordfish catch rates are largely unexplored. This study used generalized additive models fitted to longline fishery data to investigate relationships between environmental variables and catch rates to understand the processes influencing swordfish distributions in the Indian Ocean. The catch rates and distribution of swordfish in the Indian Ocean were sensitive to climatic and environmental variation. The environmental effects differ between the northwest and southwest Indian Ocean. The predicted relative abundance reveals a notable increase along the western coast of the northwest Indian Ocean during nominal Indian Ocean Dipole and negative Southern Indian Ocean Dipole (IOSD) events, and is related to the changes in net primary production and shallow mixed layer depth. The predicted relative abundances also show that the distribution of lower sea surface temperature and sea surface height deviation surrounding Madagascar increased during negative IOSD events in the southwest Indian Ocean.

Countries may utilize a long coastline in relation to their landmass as a resource to develop their maritime economy. This paper argues that ASEAN countries differ in utilizing their maritime potential. As a basis for further comparative... more

Countries may utilize a long coastline in relation to their landmass as a resource to develop their maritime economy. This paper argues that ASEAN countries differ in utilizing their maritime potential. As a basis for further comparative studies the Center for Policy Research and International Studies (CenPRIS) in Penang developed a set of indicators to measure the maritime potential of nations, the state of their maritime industries, and the degree to which the maritime potential has actually been utilized.

Effects of heavy metals [copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni), manganese (Mn), iron (Fe), Aluminum (Al), cadmium (Cd), mercury (Hg), stannum (Sn), and lead (Pb)] present in Tubruk harbor (polluted site) comparing to Umm... more

Effects of heavy metals [copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni), manganese (Mn), iron (Fe), Aluminum (Al), cadmium (Cd), mercury (Hg), stannum (Sn), and lead (Pb)] present in Tubruk harbor (polluted site) comparing to Umm Hufayan lagoon water (control) on liver and kidney performance of Mugil cephalus captured from both sites were investigated. For this purpose, surface water samples of both chosen sites were compared in terms of heavy metals concentrations, pH, and dissolved oxygen. Mullet fish were captured from both sites and blood samples were taken from the fish and sent to the lab for liver and kidney function tests. The results showed that heavy metals levels were significantly higher in Tubruk than those in Umm Hufayan lagoon. Additionally, significantly higher total protein and albumin levels were found in the blood serum of M. cephalus of Umm Hufayan, compared to Tubruk harbor fish samples; however, higher levels of bilirubin (BR), alanine transaminase (ALT), ...

Length-weight relationship, condition (K) and relative condition factor (Kn) for male, female and combined sexes of a mugilid species, Mugil incilis were analyzed during the period from January 2014 to December 2014. During the study, a... more

Length-weight relationship, condition (K) and relative condition factor (Kn) for male, female and combined sexes of a mugilid species, Mugil incilis were analyzed during the period from January 2014 to December 2014. During the study, a total of 80 fish samples were collected from the landing sites on Indus River at district Sukkur that included 48 males and 32 females. All specimens were ranging from 12.0cm to 14.5cm in total length (TL) and 23.2g to 38.5g in body weight (BW). While total length of males ranged from 12.4cm to 14.4cm and body weight 23.2g to 38.1g and female’s total length ranged from 12.0cm to14.4cm and body weight 25.1g to 38.5g. The result of the present study revealed that a moderate correlation (r>0.60, ttest; p<0.05) occurred between the length and weight of this species which was found to be significant. The negative allometric growth pattern (b<3.0) was observed and was found to be highly significant (t-test; p<0.05) for male, female and for comb...

SUMMARYVarious management approaches have been proposed to address the alarming depletion of marine coastal resources. Prominent among them are community-based management and the establishment of marine protected areas (MPAs). The overall... more

SUMMARYVarious management approaches have been proposed to address the alarming depletion of marine coastal resources. Prominent among them are community-based management and the establishment of marine protected areas (MPAs). The overall poor performance of MPAs can be traced to a failure to effectively include local communities in the design and implementation of relevant measures. Recent efforts have incorporated aspects of community-based management into a hybrid form of management, which ideally builds upon existing local management practices. A key challenge lies in the development of appropriate frameworks that allow for the successful participation of local communities in management. A review of studies on MPA design and community-based marine resource management and fieldwork observations provides suggestions on how to address current socioeconomic shortcomings in MPA design and implementation, successfully involving local communities in order to provide a better local basi...

The objective of this present study is to determine the optimum concentration for glutathione in the cryopreservation of seurukan fish (Osteochilus vittatus) spermatozoa. A completely randomized design (CRD) was used with 6 treatments and... more

The objective of this present study is to determine the optimum concentration for glutathione in the cryopreservation of seurukan fish (Osteochilus vittatus) spermatozoa. A completely randomized design (CRD) was used with 6 treatments and 3 replications. The Seurukan fish sperm was diluted in extender with a ratio of 1:20 (sperm: extender), then glutathione was added at a concentration of 0, 10, 20, 30, 40 and 50 mg L À1. Next, the sperm thawed at 39e40 C for 3 min and mixed with 100 eggs which were randomly selected. The success of the fertilized egg was observed 6 h after fertilization, while the hatching rate was examined 60 h after fertilization. The ANOVA test showed that the addition of glutathione significant affected the sperms motility, fertility and hatching rate of seurukan fish Osteo-chilus vittatus eggs (P < 0.05). By segregation the fresh sperm, a higher sperm motility rate was recorded with an addition of 30 mgL À1 of glutathione (63.00 ± 5.89), however, this value was not significantly different from using concentration of 10 and 20 mg L À1. A higher fertilization rate was produced using glutathione concentration of 50 mg L À1 (51.33 ± 17.01); however, it was also not significantly different from the concentration of 20, 30 and 40 mgL À1. In addition, a higher hatching rate was also recorded using glutathione concentration of 50 mg L À1 (40.33 ± 12.89), this value was not significantly different from using 40 mgL À1 glutathione. Hence, a conclusion was drawn that the optimum concentration of glutathione is 40 mg L À1 of diluent.

In the present investigation, the effect of sub lethal concentration of the garlic aqueous extract on fish Channa punctatus were studied after 24 hrs, 48 hrs, 72 hrs and 96 hrs exposure respectively. Different concentrations of garlic (10... more

In the present investigation, the effect of sub lethal concentration of the garlic aqueous extract on fish Channa punctatus were studied after 24 hrs, 48 hrs, 72 hrs and 96 hrs exposure respectively. Different concentrations of garlic (10 ppm/lit, 15 ppm/lit) used against Protein content of fish and results showed the gradual decrease in the protein content, ranging (106.14 – 91.65 mg/gm) for 10 ppm/lit for (24 hrs – 96 hrs) and (103.90-88.13 mg/gm) for 15 ppm/lit respectively

The taxonomic composition of the metazoan parasites found in the stomach of 629 specimens of the "Patagonian toothfish" Dissostichus eleginoides Smitt, 1898, from two localities in southern Chile (Lebu 36 • 00 S; Quellón 48 • 49 S), is... more

The taxonomic composition of the metazoan parasites found in the stomach of 629 specimens of the "Patagonian toothfish" Dissostichus eleginoides Smitt, 1898, from two localities in southern Chile (Lebu 36 • 00 S; Quellón 48 • 49 S), is recorded. More than 58,000 parasite specimens belonging to 9 taxa were registered. Adult worms were represented by the hemiurids Gonocerca phycidis Manter 1925, Lecithochirium genypteri Luhe 1905, Brachyphallus crenatus (Rudolphi 1802), and Derogenes varicus (Muller 1784) and the nematode Hysterothylacium sp. Ward & Magath 1917. Larval forms of anisakid nematodes, an acanthocephalan (Corynosoma sp.), a trypanorhynch cestode (Hepatoxylon trichiuri (Holten 1802)) and an unidentified pseudophyllidean cestode were also obtained. Parasitological evidence, based on univariate and multivariate analysis, does not support either the existence of discrete stocks, migratory movements between areas or seasonality in pattern of infection.

Threats to and loss of seagrass ecosystems globally, impact not only natural resources but also the lives of people who directly or indirectly depend on these systems. Seagrass ecosystems play a multi-functional role in human well-being,... more

Threats to and loss of seagrass ecosystems globally, impact not only natural resources but also the lives of people who directly or indirectly depend on these systems. Seagrass ecosystems play a multi-functional role in human well-being, e.g. food through fisheries, control of erosion and protection against floods. Quantifying these services reveals their contributions to human well-being and helps justify seagrass conservation. There has been no comprehensive assessment as to whether seagrass ecosystem services are perceived to vary over the globe or amongst genera. Our study compiles the most complete list of ecosystem services provided by seagrasses so far, including bioregional-and genus-specific information from expert opinion and published studies. Several seagrass ecosystem services vary considerably in their (known) provision across genera and over the globe. Seagrasses genera are clearly not all equal with regard to the ecosystem services they provide. As seagrass genera are not evenly distributed over all bioregions, the presence of an ecosystem service sometimes depends on the genera present. Larger sized seagrass genera (e.g. Posidonia, Enhalus) are perceived to provide more substantial and a wider variety of ecosystem services than smaller species (e.g. Halophila, Lepilaena). Nevertheless, smaller species provide important services. Our findings point out data gaps, provide new insight for more efficient management and recommend caution in economic valuation of seagrass services worldwide.

Opsaridium microlepis migrates for spawning during the rainy season (November to May) to major affluent rivers. Linthipe River is one of the major rivers, into which this species migrates. Determination of reproductive seasonality of O.... more

Opsaridium microlepis migrates for spawning during the rainy season (November to May) to major affluent rivers. Linthipe River is one of the major rivers, into which this species migrates. Determination of reproductive seasonality of O. microlepis is paramount in the improved management of this endangered species. Reproductive seasonality of O. microlepis in the Linthipe River in Central Malawi was estimated using 546 specimens for 12 months. The GSI (Gonadosomatic Index) ranged between 5.6% and 13% for females and between 0.3% and 1.4% for males, respectively. GSI variation between the months was significantly different (one-way ANOVA (analysis of variance), P < 0.05). The peak breeding activity was observed between January to April. This was at the onset of rainy season while the condition factor of O. microlepis was found to be variable with lowest value in the month of August. The study revealed that for O. microlepis fishery to be sustainably exploited, proper management regimes should be instituted along the migratory rivers during the peak breeding periods. These sustainable methods need to be managed in a participatory manner together with the majority of people living along these rivers.

During 1997, quarterly exploratory cruises of the R/V``Archipelago'' were carried out in order to study the deep water crab Chaceon af®nis [Res. Camp. Sci. Mo Ânaco Fasc. VII (1894) 1], South of Pico island (Azores) and at the Menez Gwen... more

During 1997, quarterly exploratory cruises of the R/V``Archipelago'' were carried out in order to study the deep water crab Chaceon af®nis [Res. Camp. Sci. Mo Ânaco Fasc. VII (1894) 1], South of Pico island (Azores) and at the Menez Gwen hydrothermal vent area (SW of the Azores, within the Azorean Economic Exclusive Zone). The crabs were caught with bottom traps according to a speci®ed survey design. Different areas between 300 and 1200 m depth were surveyed. Information from previous collections was also compiled and analysed. A total of 1153 crabs (726 males and 427 females) were caught at depths ranging from 600 to 1100 m on rocky and/or muddy bottoms. Size ranged from 39 to 177 mm carapace length (CL), the males being larger than females. Males were relatively more abundant at depths <800 m and females relatively more abundant at depths >800 m. The greatest abundance occurred at depths from 700 to 800 m. Ovigerous females, which were consistently >70 mm CL, were found only from October to March. An annual reproductive cycle is suggested. Size at ®rst maturity for the females, was estimated to be within the size range of 83±97 mm CL. Other ecological and biological information such as distribution, morphometric aspects related to reproduction, occurrence of parasites and epibionts, are discussed, as well as by-catch species.

We compared the community structure of benthic algae inside and outside pomacentrid damselfish (Stegastes nigricans) territories in a moat at Sesoko Island, Okinawa, Japan. S. nigricans maintained ''algae farms'' that were dominated by... more

We compared the community structure of benthic algae inside and outside pomacentrid damselfish (Stegastes nigricans) territories in a moat at Sesoko Island, Okinawa, Japan. S. nigricans maintained ''algae farms'' that were dominated by the filamentous rhodophyte, Womersleyella setacea. Species richness and biomass were higher inside damselfish territories than outside, while species diversity and evenness were higher outside. Detrended correspondence analysis (DCA) based on species composition showed that the dominance of W. setacea was maintained throughout the year in all samples collected from inside damselfish territories. The observed strong dominance of filamentous rhodophytes was consistent with the findings of most studies on damselfish territories worldwide. However, the dominance of a single species of alga and low species diversity inside the territories was in contrast to the findings of previous studies, in which the reduction of grazing pressure caused intermediate disturbance and enhanced algal species diversity. This discrepancy in algal species diversity inside the damselfish territories seems to have been caused by unique characteristics of the alga and the fish. W. setacea traps sediment, which reduces the availability of firm substrata for attachment and inhibits the recruitment of some algae. Moreover, S. nigricans ''weeds'' indigestible calcareous and thicker algae. The algal assemblage outside damselfish territories varied among samples, and included mat-forming cyanophytes (Calothrix aeruginosa and Calothrix codicola), a prostrate laminar phaeophyte (Padina sp.), thin and small-scaled algae (Cladophora sp. and Feldmannia indica), finely branched filamentous rhodophytes (Taenioma perpusillum and Herposiphonia obscura), and a coarsely branched rhodophyte (Gelidiopsis variabilis).

The current situation observed in the seafood industry demonstrates that responsible and certified seafood produced in Asia as well as other developing regions is often exported out to Western markets such as Europe and the US, due to a... more

The current situation observed in the seafood industry demonstrates that responsible and certified seafood produced in Asia as well as other developing regions is often exported out to Western markets such as Europe and the US, due to a higher demand and higher willingness to pay. This renders responsible and certified seafood to be shipped out of Asia and results in a market where responsible and certified seafood is systematically underrepresented. Hence, the lack of supply of responsible seafood from regional sources has hindered companies’ efforts to source responsibly, despite a commitment to do so.
With Asia’s increasing disposable income and growing awareness by consumers for responsible and certified seafood, greater opportunities can be leveraged upon by World Wide Fund for Nature (WWF) to increase the supply and demand of responsible seafood in the region.
The Responsible Seafood Tool (RESET) is developed as WWF believes that there is opportunity for change in empowering businesses in Asia to source more responsibly, particularly for a local favourite - seafood. Responsible seafood sourcing helps to reduce negative consequences to the environment, in the form of biodiversity loss, seascape degradation, and resource depletion, as well as to reduce lost livelihoods displaced by depleted fishstock or polluted landscapes and seascapes. The tool seeks to lower the barriers for businesses to source for responsible seafood, and to directly mobilize improved management and performance of fisheries and aquaculture in Asia.
In a nutshell, RESET aims to provide easy access to the supply of responsible seafood for interested buyers, while also supporting Asian aquaculture and fisheries by providing business incentives for certification. Seafood buyers enjoy the access of a variety of responsible seafood from Asia, at the same time, they enable WWF to propel responsible seafood producers along their journey to achieve Aquaculture Stewardship Council (ASC) or Marine Stewardship Council (MSC) certification.

A newly analytical method based on QuEChERS extraction followed by gas chromatography with mass spectrometry (GC-MS) analysis was developed and validated for the quantification of 18 PCBs in wild (from Matosinhos Beach, Portugal) and... more

A newly analytical method based on QuEChERS extraction followed by gas chromatography with mass spectrometry (GC-MS) analysis was developed and validated for the quantification of 18 PCBs in wild (from Matosinhos Beach, Portugal) and cultivated (from Ria de Arousa, Spain) mussel samples, pooled by sex. Wild animals showed higher PCB levels than cultivated mussels, with males from both origins, presenting an upper contamination profile comparing with females. This fact seems to be correlated with few biometric parameters, but other interdependencies, not addressed herein, such as distinct lipid contents between sexes, as a consequence of the gametogenic stage, may also explain this data. Overall, data reiterate the importance of investigating the presence of PCBs in marine biological samples, which can act both as bioindicators of environmental contamination, either as food quality controls for human health.

A new method for the molecular detection of the fish pathogens, infectious haematopoietic necrosis virus (IHNV) and infectious salmon anaemia virus (ISAV), is described. By employing molecular padlock probe (MPP) technology combined with... more

A new method for the molecular detection of the fish pathogens, infectious haematopoietic necrosis virus (IHNV) and infectious salmon anaemia virus (ISAV), is described. By employing molecular padlock probe (MPP) technology combined with rolling circle amplification (RCA) and hyperbranching (Hbr), it is possible to detect RNA target sequence from these viruses at levels comparable with those detected by the polymerase chain reaction (PCR), but without prior reverse transcription. The use of MPP technology combined with RCA and Hbr for the detection of IHNV and ISAV in fish exhibited selectivity comparable with that of PCR while potentially reducing the time and cost required for analysis. The method described was used to detect as few as 10 4 DNA oligonucleotide targets and was sequence-specific at the single base level. Viral RNA could be detected directly, either alone or in the presence of non-viral RNA from fish tissue. This technology is applicable for detecting a variety of microbes, in addition to IHNV and ISAV, and is ideal for further integration into a biosensor platform for on-site diagnosis of pathogen infection in fish.

Scanning proton microprobe (SPM) analysis and imaging was used to map the distribution of zinc in otoliths of anadromous and non-anadromous Arctic char (Salvelinus alpinus) from the Canadian Arctic. Zinc distribution patterns were... more

Scanning proton microprobe (SPM) analysis and imaging was used to map the distribution of zinc in otoliths of anadromous and non-anadromous Arctic char (Salvelinus alpinus) from the Canadian Arctic. Zinc distribution patterns were oscillatory with concentrations ranging from 35 to 240 ppm. Superimposition of the zinc distribution on optical images of the otoliths permitted correlation of zinc uptake with annular structure in the otoliths and with strontium patterns from the same otolith. Well defined oscillations of zinc concentrations were observed in the otoliths, particularly in the first few years in all samples. In anadromous fish, these overlapped with the onset of the strontium oscillations that were indicative of anadromy and then declined; in non-anadromous fish the oscillations generally continued to later years. Oscillatory zoning of zinc may indicate: (1) variations in the concentration of zinc in water; (2) variations in nutrient availability in the environment; (3) temperature variations in the habitat occupied; or (4) a combination of zinc concentration, nutrient availability or temperature changes. As such, the systematic distribution of zinc in otoliths has the potential to provide temporally constrained information on fish habitat and/or fish biology.

Previous research has alluded to the potential of metals being absorbed by fish after ingesting fishing hooks, which may have adverse effects on fish health and the organisms that consume them. Subsequently, this study aimed to quantify... more

Previous research has alluded to the potential of metals being absorbed by fish after ingesting fishing hooks, which may have adverse effects on fish health and the organisms that consume them. Subsequently, this study aimed to quantify the potential of mulloway (Argyrosomus japonicus) to absorb metals during the decay of ingested nickel-plated carbon-steel hooks. Twenty-five treatment fish were allowed to ingest nickel-plated carbon-steel hooks during angling and then monitored with 25 controls (untreated fish) for up to 42 days for hook ejection and mortality. Blood, liver and muscle samples were collected from treatment, control and 14 wild-caught individuals to determine the concentrations of chromium, cobalt, copper, iron, manganese and nickel. The results showed that increased oxidation influenced hook ejection, and that hook-ingested fish had significantly elevated concentrations of nickel in their liver and blood, but not muscle. This research has shown that there is an avenue for metal absorption from ingested hooks.

Real-time PCR assays are being increasingly applied to the detection of fish pathogens due to their sensitivity, specificity and potential for high throughput sample processing. Such assays allow for the ready and efficient inclusion of... more

Real-time PCR assays are being increasingly applied to the detection of fish pathogens due to their sensitivity, specificity and potential for high throughput sample processing. Such assays allow for the ready and efficient inclusion of appropriate quality controls which are fundamental to scientific integrity and to satisfying the demands of diagnostic test accreditation. In this article, we report development of a universal positive control strategy for real-time PCR assays, which has been used to support and improve a previously published method for detection of infectious salmon anaemia virus (ISAV). The strategy employed uses an RNA mimic template, which is based on the ISAV segment 8 target sequence but includes an artificial universal positive control sequence. Inclusion of this sequence, which is targeted by a second specific probe carrying a different fluorophore to the primary assay, allows for convenient screening of all real-time PCR reactions for the presence of contaminating positive control material. The development of readily distinguishable artificial positive control material offers distinct advantages to real-time PCR assays over using control material derived from clinical material.

The carbon (δ13C) and nitrogen (δ15N) values of Sander vitreus scales differed pre and post-introduction in treatment lakes among years following the introduction of Micropterus dolomieu. No difference of δ13C and δ15N in S. vitreus... more

The carbon (δ13C) and nitrogen (δ15N) values of Sander vitreus scales differed pre and post-introduction in treatment lakes among years following the introduction of Micropterus dolomieu. No difference of δ13C and δ15N in S. vitreus scales was found in control lakes where M. dolomieu were not introduced. In treatment lakes, S. vitreus δ15N increased and δ13C decreased. No relationship was found between S. vitreus and M. dolomieu abundance in the two treatment lakes. Size
structure of S. vitreus and M. dolomieu was negatively correlated and condition of the two species was positively correlated. Although S. vitreus feeding habits may have changed in the treatment lakes after M. dolomieu introductions, evidence suggests that fitness-related factors (i.e. abundance and condition) of S. vitreus remained unchanged, indicating S. vitreus and M. dolomieu may coexist
where M. dolomieu have been introduced.

The Brazilian federal government has adopted DNA barcoding (i.e. analysing about 650 base pairs of the COI mitochondrial gene) as a standardised method in a nationwide programme for routine and systematic regulation of processed seafood... more

The Brazilian federal government has adopted DNA barcoding (i.e. analysing about 650 base pairs of the COI mitochondrial gene) as a standardised method in a nationwide programme for routine and systematic regulation of processed seafood products. Here, we report rates and trends of a forensic programme which sampled products with twenty-eight commercial fish names (N = 255) confiscated by official governmental officers from 14 states, and which also included imports from 8 countries. A mislabelling rate of 17.3% (44 samples) was recovered when comparing the DNA barcode identification of fish products to the official Brazilian list of species and commercial names. No statistical differences in mislabelling rates between geopolitical regions was detected (G = 2.4, N = 5, p = 0.66). The number of mislabelled samples was not correlated to samples size per commercial name (r = 0.34, N = 29, p = 0.07), but instead, misla-belling was positively correlated to the number of species detected (r = 0.75, N = 29, p < 0.00), suggesting that more surveillance should be given to species with less well-defined commercial names. The programme resulted in financial penalties being applied according to the amount of mislabelling detected. Moreover, companies caught selling mislabelled products were further inspected until the company proved that their production was normalised according to Brazilian labelling regulations. A systematic nationwide forensic governmental programme may lead to more sustainable and trusted fisheries activities allowing consumers to make informed choices when buying seafood products.

This paper was selected for presentation by an FISON Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Fisheries... more

This paper was selected for presentation by an FISON Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Fisheries Society of Nigeria and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Fisheries Society of Nigeria, its officers, or members. Papers presented at FISON meetings are subject to publication review by Editorial Committees of the Fisheries Society of Nigeria. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the Fisheries Society of Nigeria is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgement of where and by whom the paper was presented. Write Librarian, Fisheries Society of Nigeria (FISON),

Nitrogen (N) and phosphorus (P) wastes produced by Nile tilapia Oreochromis niloticus L. fed Azolla, an aquatic at-mospheric nitrogen fixing fern, was evaluated for 90 days in pond experiment. Six isonitrogenous (29.2 % crude protein) and... more

Nitrogen (N) and phosphorus (P) wastes produced by Nile tilapia Oreochromis niloticus L. fed Azolla, an aquatic at-mospheric nitrogen fixing fern, was evaluated for 90 days in pond experiment. Six isonitrogenous (29.2 % crude protein) and isoenergetic (16.9 Kj·g–1) diets A0, A10, A20, A30, A40 and A50, containing 0%, 10%, 20%, 30%, 40 % and 50 % of Azolla meal (AM) respectively, as partial fishmeal (FM) substitutes, was provided to experimental fish. The Azolla-free diet A0 served as a control. Fish specific growth rate (SGR) was higher with the control diet, the lower values being obtained in A50-fed fish (P < 0.05). Crude protein and P content in experimental fish showed similar values. Evaluation of the nutrient wasted show identical values (84.8 %- 87.8 % of supplied) for total P (TP); while total N (TN) discharged into ponds by fish increased significantly when AM level greater than 30 % in diets (P < 0.05), amounting 63.9 %-74.2 % of that supplied. From these findings, t...

Aim: The aim of the current investigation was to screen the presence of Staphylococci spp., especially S. aureus in meat, meat products of different animal species, and some seafood sold in some retail markets in Libya using cultural and... more

Aim: The aim of the current investigation was to screen the presence of Staphylococci spp., especially S. aureus in meat, meat products of different animal species, and some seafood sold in some retail markets in Libya using cultural and molecular techniques, and to study their antibiotics resistance profiles. Materials and Methods: A total of 139 samples from red meat, meat products, and seafood were collected from many areas in Libya. Enumeration and isolation of Staphylococci spp. and S. aureus by normal cultural methods followed by molecular identification using molecular techniques by bacterial DNA extraction and partial sequencing of 16S rDNA. Results: Out of 139 samples, 112 (80.6%) were contaminated with different species of Staphylococci based on cultural characteristics of Staphylococci on Baird-Parker medium, for which S. aureus was detected in only 32 samples (23%). However, only six out of 18 (33.3%) isolates sent for sequencing were confirmed to be S. aureus using the ...

Fishes serve as indicators in ecological assessments of European large rivers. Electrofishing is the standard fishing method although it is restricted to the shallow littoral shoreline. Fish occurring in the open water zone of the main... more

Fishes serve as indicators in ecological assessments of European large rivers. Electrofishing is the standard fishing method although it is restricted to the shallow littoral shoreline. Fish occurring in the open water zone of the main channel remain consequently underestimated. Additional sampling methods that cover the mid-channel of rivers could close the electrofishing-gap, but strengths', weaknesses and gains of both electrofishing and additional sampling methods for fish-based assessments of large rivers have not been contrasted yet. We analyzed a unique dataset consisting of 2,693 fish samplings in European large rivers and compared electrofishing with the additional sampling methods trawling, seining, and driftnetting. We compiled fish metrics commonly used in fish-based assessments yielded by the different gears and highlight the differences in fish species, biodiversity metrics (Shannon Index, Evenness, Simpson Index), the Fish Region Index (FRI) and densities of fish in selected guilds (eurytopic, rheophilic, lithophilic, phytophilic, psammophilic, potamal) that are considered indicative for the degradation of habitats in large rivers. Electrofishing yielded overall highest numbers of species, biodiversity metrics and densities of fish guilds, except for the number of migratory and Habitat Directive species, the FRI and densities of potamal fish. The additional gears, predominantly trawling, captured additional rheophilic and lithophilic species. Trawling also assessed most migratory and Habitat Directive species and yielded higher densities of potamal fish as well as larger fish than electrofishing. Trawl catches further estimated higher biodiversity compared to seining, while the latter yielded higher densities of eurytopic, rheophilic, lithophilic and phytophilic fish. Drift-netting yielded the lowest estimates overall but sample size was very low. We suggest that electrofishing is an appropriate method to assess and evaluate the effects of hydromorphological degradation and rehabilitation on fish, and to guide river management. It sufficiently well represents the typical fish assemblage of large rivers despite its restriction to the shoreline. In contrast, assessing specifically Habitat Directive, migratory and rare species, as well as obtaining complete species inventories, e.g., for biodiversity assessments, requires complementary sampling of the mid-channel of large rivers by additional gears such as trawling.