Marta Söffker | University of East Anglia (original) (raw)
Papers by Marta Söffker
PloS one, 2015
Predatory interaction of marine mammals with longline fisheries is observed globally, leading to ... more Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides) fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella), sperm whales (Physeter macrocephalus), and orcas (Orcinus orca) frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited an...
Environmental Science & Technology, 2012
Genetic variation has a significant effect on behavior, fitness, and response to toxicants; howev... more Genetic variation has a significant effect on behavior, fitness, and response to toxicants; however, this is rarely considered in ecotoxicological studies. We compared fitnessrelated behavioral traits, breeding activity, and the effects of exposure to the environmental estrogen ethinylestradiol (EE 2 ) on reproduction in a laboratory (Wild Indian Karyotype, WIK) strain and a wild-caught population (Bangladesh, BLD01) of Danio rerio (zebrafish). In WIK fish, males with higher observed heterozygocity were more active reproductively and more successful in securing parentage, but these relationships were not apparent in the BLD01 fish. The frequency of reproductive behaviors increased in WIK zebrafish for exposure to 0.4 ng/L EE 2 , which was not apparent in the BLD01 zebrafish. The different strains showed the same threshold for hepatic vitellogenin gene (vtg) induction (2.2 ng EE 2 /L), but results suggested an elevated response level in the BLD01. There were no effects on total egg production up to 2.2 ng EE 2 /L in either population; however, there was reduced egg fertilization rate at 2.2 ng EE 2 /L in the BLD01 fish. These results show consistency in the general responses to EE 2 between these two genetically divergent strains of zebrafish, but also illustrate differences in their breeding biology and response sensitivities. These findings highlight the need for due consideration of the source (and genetics) of populations used in ecological risk assessment for accurate comparisons among studies.
Environmental Science & Technology, 2010
Critical Reviews in Toxicology, 2012
Endocrine disrupting chemicals (EDCs) enter aquatic ecosystems through discharged effluents, main... more Endocrine disrupting chemicals (EDCs) enter aquatic ecosystems through discharged effluents, mainly from wastewater treatment works and diffuse run off from land, and affect a wide range of aquatic biota, including fish. Evidence for altered physiology in fish as a consequence of endocrine disruption is global, with some of the most widely reported effects on sexual development and function. In recent years research has shown that fish behaviors can also be affected by EDCs which potentially has wide implications for individual fitness and population level outcomes. This review presents a critical assessment on reported effects of EDCs on behavior in fish, focusing on behaviors associated with reproduction. We investigate commonalities and differences in sexual behaviors between fish species most commonly applied in ecotoxicology, drawing out common principles for impacts of EDCs and then reviewing the evidence for, and implications of, disruptions of these behaviors after exposures to EDCs. In an analysis of the reported effects of exposure to the estrogen, ethinylestradiol, we show that life-stage at exposure is a key factor determining behavioral responses of affected populations. EDC-induced changes in behavior occur at similar concentrations as for established biomarker responses (e.g. vitellogenin induction for estrogens), indicating behavior is equally sensitive (and non-invasive) as an indicator of EDC exposure. Adopting behaviors in fish as indicators of chemical exposure and effects, however, still has many technical and interpretation challenges and there is very little information available on how behaviors under laboratory conditions equate with those occurring in wild populations.
American Midland Naturalist, 1996
The biology of littoral fauna of the Falkland Islands is largely unknown. This pilot study was la... more The biology of littoral fauna of the Falkland Islands is largely unknown. This pilot study was launched by Shallow Marine Surveys Group and was aimed at investigating life history of the Antarctic starfish, Anasterias antarctica, a dominating invertebrate predator of intertidal and subtidal, including its distribution, seasonal and ontogenetic migrations, spawning seasonality, fecundity, growth, and feeding habits. A total of 3,426 starfish were sampled in different habitats around the Falkland Islands at low tide using SCUBA diving. Sampling included measuring arm length, presence/absence of brooding and feeding; the prey was identified to the lowest taxa and measured if condition permitted. In a total of 48 broods, eggs were counted and embryonic stage assigned. This medium-sized species attains an arm length of 96 mm (85.4 g). The size increased with depth and starfish carry out seasonal bathymetric migrations with smaller animals (\30 mm) being rare in waters[10 m depth in winter. Egg laying occurs between March and July, and juvenile dispersal-mostly in October-November. Fecundity (52-363 eggs) and egg/offspring size increase with maternal size. Juvenile starfish are of ca. 2 mm arm length and grow to 9-11 mm in 1 year. Feeding intensity is at a maximum before and after the reproductive period. Females might occasionally resume feeding when they are still brooding a small number of juveniles. The starfish prey upon isopods (Sphaeromatidae), molluscs Pareuthria spp. and variety of gastropods, bivalves chitons, barnacles, and also scavenges. Prey size increases with starfish size.
Proceedings of the National Academy of Sciences of the United States of America, Jan 2, 2015
Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on... more Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on wildlife populations could be exacerbated by climate change, especially in species with environmental sex determination. Endangered species may be particularly at risk because inbreeding depression and stochastic fluctuations in male and female numbers are often observed in the small populations that typify these taxa. Here, we assessed the interactive effects of water temperature and EDC exposure on sexual development and population viability of inbred and outbred zebrafish (Danio rerio). Water temperatures adopted were 28 °C (current ambient mean spawning temperature) and 33 °C (projected for the year 2100). The EDC selected was clotrimazole (at 2 μg/L and 10 μg/L), a widely used antifungal chemical that inhibits a key steroidogenic enzyme [cytochrome P450(CYP19) aromatase] required for estrogen synthesis in vertebrates. Elevated water temperature and clotrimazole exposure independent...
PloS one, 2015
Predatory interaction of marine mammals with longline fisheries is observed globally, leading to ... more Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides) fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella), sperm whales (Physeter macrocephalus), and orcas (Orcinus orca) frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited an...
Environmental Science & Technology, 2012
Genetic variation has a significant effect on behavior, fitness, and response to toxicants; howev... more Genetic variation has a significant effect on behavior, fitness, and response to toxicants; however, this is rarely considered in ecotoxicological studies. We compared fitnessrelated behavioral traits, breeding activity, and the effects of exposure to the environmental estrogen ethinylestradiol (EE 2 ) on reproduction in a laboratory (Wild Indian Karyotype, WIK) strain and a wild-caught population (Bangladesh, BLD01) of Danio rerio (zebrafish). In WIK fish, males with higher observed heterozygocity were more active reproductively and more successful in securing parentage, but these relationships were not apparent in the BLD01 fish. The frequency of reproductive behaviors increased in WIK zebrafish for exposure to 0.4 ng/L EE 2 , which was not apparent in the BLD01 zebrafish. The different strains showed the same threshold for hepatic vitellogenin gene (vtg) induction (2.2 ng EE 2 /L), but results suggested an elevated response level in the BLD01. There were no effects on total egg production up to 2.2 ng EE 2 /L in either population; however, there was reduced egg fertilization rate at 2.2 ng EE 2 /L in the BLD01 fish. These results show consistency in the general responses to EE 2 between these two genetically divergent strains of zebrafish, but also illustrate differences in their breeding biology and response sensitivities. These findings highlight the need for due consideration of the source (and genetics) of populations used in ecological risk assessment for accurate comparisons among studies.
Environmental Science & Technology, 2010
Critical Reviews in Toxicology, 2012
Endocrine disrupting chemicals (EDCs) enter aquatic ecosystems through discharged effluents, main... more Endocrine disrupting chemicals (EDCs) enter aquatic ecosystems through discharged effluents, mainly from wastewater treatment works and diffuse run off from land, and affect a wide range of aquatic biota, including fish. Evidence for altered physiology in fish as a consequence of endocrine disruption is global, with some of the most widely reported effects on sexual development and function. In recent years research has shown that fish behaviors can also be affected by EDCs which potentially has wide implications for individual fitness and population level outcomes. This review presents a critical assessment on reported effects of EDCs on behavior in fish, focusing on behaviors associated with reproduction. We investigate commonalities and differences in sexual behaviors between fish species most commonly applied in ecotoxicology, drawing out common principles for impacts of EDCs and then reviewing the evidence for, and implications of, disruptions of these behaviors after exposures to EDCs. In an analysis of the reported effects of exposure to the estrogen, ethinylestradiol, we show that life-stage at exposure is a key factor determining behavioral responses of affected populations. EDC-induced changes in behavior occur at similar concentrations as for established biomarker responses (e.g. vitellogenin induction for estrogens), indicating behavior is equally sensitive (and non-invasive) as an indicator of EDC exposure. Adopting behaviors in fish as indicators of chemical exposure and effects, however, still has many technical and interpretation challenges and there is very little information available on how behaviors under laboratory conditions equate with those occurring in wild populations.
American Midland Naturalist, 1996
The biology of littoral fauna of the Falkland Islands is largely unknown. This pilot study was la... more The biology of littoral fauna of the Falkland Islands is largely unknown. This pilot study was launched by Shallow Marine Surveys Group and was aimed at investigating life history of the Antarctic starfish, Anasterias antarctica, a dominating invertebrate predator of intertidal and subtidal, including its distribution, seasonal and ontogenetic migrations, spawning seasonality, fecundity, growth, and feeding habits. A total of 3,426 starfish were sampled in different habitats around the Falkland Islands at low tide using SCUBA diving. Sampling included measuring arm length, presence/absence of brooding and feeding; the prey was identified to the lowest taxa and measured if condition permitted. In a total of 48 broods, eggs were counted and embryonic stage assigned. This medium-sized species attains an arm length of 96 mm (85.4 g). The size increased with depth and starfish carry out seasonal bathymetric migrations with smaller animals (\30 mm) being rare in waters[10 m depth in winter. Egg laying occurs between March and July, and juvenile dispersal-mostly in October-November. Fecundity (52-363 eggs) and egg/offspring size increase with maternal size. Juvenile starfish are of ca. 2 mm arm length and grow to 9-11 mm in 1 year. Feeding intensity is at a maximum before and after the reproductive period. Females might occasionally resume feeding when they are still brooding a small number of juveniles. The starfish prey upon isopods (Sphaeromatidae), molluscs Pareuthria spp. and variety of gastropods, bivalves chitons, barnacles, and also scavenges. Prey size increases with starfish size.
Proceedings of the National Academy of Sciences of the United States of America, Jan 2, 2015
Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on... more Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on wildlife populations could be exacerbated by climate change, especially in species with environmental sex determination. Endangered species may be particularly at risk because inbreeding depression and stochastic fluctuations in male and female numbers are often observed in the small populations that typify these taxa. Here, we assessed the interactive effects of water temperature and EDC exposure on sexual development and population viability of inbred and outbred zebrafish (Danio rerio). Water temperatures adopted were 28 °C (current ambient mean spawning temperature) and 33 °C (projected for the year 2100). The EDC selected was clotrimazole (at 2 μg/L and 10 μg/L), a widely used antifungal chemical that inhibits a key steroidogenic enzyme [cytochrome P450(CYP19) aromatase] required for estrogen synthesis in vertebrates. Elevated water temperature and clotrimazole exposure independent...