Mirta Teichberg - Academia.edu (original) (raw)

Papers by Mirta Teichberg

Changes in the coral reef complex can affect predator-prey relationships, resource availability a... more Changes in the coral reef complex can affect predator-prey relationships, resource availability and niche utilisation in the associated fish community, which may be reflected in decreased stability of the functional traits present in a community. This is because particular traits may be favoured by a changing environment, or by habitat degradation. Furthermore, other traits can be selected against because degradation can relax the association between fishes and benthic habitat. We characterised six important ecological traits for fish species occurring at seven sites across a disturbed coral reef archipelago in Indonesia, where reefs have been exposed to eutrophication and destructive fishing practices for decades. Functional diversity was assessed using two complementary indices (FRic and RaoQ) and correlated to important environmental factors (live coral cover and rugosity, representing local reef health, and distance from shore, representing a cross-shelf environmental gradient). Indices were examined for both a change in their mean, as well as temporal (short-term; hours) and spatial (cross-shelf) variability, to assess whether fish-habitat association became relaxed along with habitat degradation. Furthermore , variability in individual traits was examined to identify the traits that are most affected by habitat change. Increases in the general reef health indicators, live coral cover and rugosity (correlated with distance from the mainland), were associated with decreases in the variability of functional diversity and with community-level changes in the abundance of several traits (notably home range size, maximum length, microalgae, detritus and small invertebrate feeding and reproductive turnover). A decrease in coral cover increased variability of RaoQ while rugosity and distance both inversely affected variability of FRic; however, averages for these indices did not reveal patterns associated with the environment. These results suggest that increased degradation of coral reefs is associated with increased variability in fish community functional composition resulting from selective impacts on specific traits, thereby affecting the functional response of these communities to increasing perturbations.

Bulletin of Marine Science, 2000

Limnology and Oceanography, 2015

Localized impacts, such as eutrophication and overfishing, have been identified as major threats ... more Localized impacts, such as eutrophication and overfishing, have been identified as major threats to reefs worldwide, resulting in changes in coral reef community composition, from coral-dominance to algaldominance. Herbivory by fishes is frequently cited as a key process structuring benthic community response to stressors. Here, we experimentally tested the capacity of herbivorous fishes to remove macroalgae along an onshore-offshore spatial gradient in the Spermonde Archipelago, Indonesia; a coral reef system exposed to long-term anthropogenic disturbances. Bioassays of Sargassum and Padina spp. were collected from the reef flat and transplanted onto the reef slope at five islands varying in distance (1-55 km) from the coastline and city of Makassar, South Sulawesi. Supplementary underwater video deployment and fish surveys were used to identify species-specific differences in herbivore communities and rates of algal removal. Over a 24 h period, Padina was almost completely removed from the two outermost islands, but removal declined toward shore. With the exception of the site closest to Makassar, more than 50% of all transplanted macroalgae were removed. Species diversity of algal-consuming fishes and total bites increased toward off-shore, with only one species, Siganus virgatus (Siganidae), feeding at all sites. These changes in herbivore communities underline the capacity for functional resilience under varying levels of reef degradation. Our results exemplify the complexities of ecological functioning along environmental gradients.

We incubated the bottles in a growth chamber on a 15:9 h light: dark cycle at a light intensity o... more We incubated the bottles in a growth chamber on a 15:9 h light: dark cycle at a light intensity of 280 -350 E m Ϫ2 s Ϫ1 and a temperature of 24 to 29°C. All treatments were sampled initially, and on days 1, 2, and 4.

The Biological bulletin, 2002

Receiving coastal waters and estuaries are among the most nutrient-enriched environments on earth... more Receiving coastal waters and estuaries are among the most nutrient-enriched environments on earth, and one of the symptoms of the resulting eutrophication is the proliferation of opportunistic, fast-growing marine seaweeds. Here, we used a widespread macroalga often involved in blooms, Ulva spp., to investigate how supply of nitrogen (N) and phosphorus (P), the two main potential growth-limiting nutrients, influence macroalgal growth in temperate and tropical coastal waters ranging from low-to high-nutrient supplies. We carried out N and P enrichment field experiments on Ulva spp. in seven coastal systems, with one of these systems represented by three different subestuaries, for a total of nine sites. We showed that rate of growth of Ulva spp. was directly correlated to annual dissolved inorganic nitrogen (DIN) concentrations, where growth increased with increasing DIN concentration. Internal N pools of macroalgal fronds were also linked to increased DIN supply, and algal growth rates were tightly coupled to these internal N pools. The increases in DIN appeared to be related to greater inputs of wastewater to these coastal waters as indicated by high d 15 N signatures of the algae as DIN increased. N and P enrichment experiments showed that rate of macroalgal growth was controlled by supply of DIN where ambient DIN concentrations were low, and by P where DIN concentrations were higher, regardless of latitude or geographic setting. These results suggest that understanding the basis for macroalgal blooms, and management of these harmful phenomena, will require information as to nutrient sources, and actions to reduce supply of N and P in coastal waters concerned.

Oecologia, Jan 4, 2015

Ocean acidification studies in the past decade have greatly improved our knowledge of how calcify... more Ocean acidification studies in the past decade have greatly improved our knowledge of how calcifying organisms respond to increased surface ocean CO2 levels. It has become evident that, for many organisms, nutrient availability is an important factor that influences their physiological responses and competitive interactions with other species. Therefore, we tested how simulated ocean acidification and eutrophication (nitrate and phosphate enrichment) interact to affect the physiology and ecology of a calcifying chlorophyte macroalga (Halimeda opuntia (L.) J.V. Lamouroux) and its common noncalcifying epiphyte (Dictyota sp.) in a 4-week fully crossed multifactorial experiment. Inorganic nutrient enrichment (+NP) had a strong influence on all responses measured with the exception of net calcification. Elevated CO2 alone significantly decreased electron transport rates of the photosynthetic apparatus and resulted in phosphorus limitation in both species, but had no effect on oxygen prod...

Journal of Experimental Marine Biology and Ecology, 2014

Despite the increasing dominance of turf algae in coral reefs, few studies have investigated thei... more Despite the increasing dominance of turf algae in coral reefs, few studies have investigated their physiological and ecological responses to changes in abiotic factors. We tested the effects of depth and ultraviolet radiation on turf algae at different levels of successional stages using two experiments. Depth-related differences were found for all turf algal communities, characterized by a higher amount of the cyanobacteria taxon Dichothrix and the red filamentous genera Poly-/Herposiphonia in the shallow and the appearance of oscillating cyanobacteria in deeper waters. In the first experiment, cross-depth transplantation of 153 days old communities influenced percentage cover, biomass and taxa composition. Downward transplantation lowered overall biomass and abundance of the foraminifera Sorites, whereas the crustose green alga Pringsheimiella and filamentous cyanobacteria colonized the communities. A nearly reverse pattern was observed in upward transplanted communities. Overall we distinguished between sensitive taxa, like Oscillatoria, and taxa able to acclimate to alterations in their environment, like Pringsheimiella, Poly/Herposiphonia and Dichothrix. In the second experiment, algae grown for 285 days at 5 m were exposed together with a set of sterile settlement tiles to three UVR regimes at 2 m for 22 days. UVR had no effect on turf algal communities regardless of successional stage. This study highlights the presence of high light and UV tolerant species. The high UV tolerance of turf communities may confer a competitive advantage over other more sensitive coral reef biota, such as corals. This study demonstrates that turf algae are dynamic communities exhibiting species-specific resistance to environmental changes.

Overall the epiphytic community needs further research as they will spread conform with their hos... more Overall the epiphytic community needs further research as they will spread conform with their hosts over the reefs in future. Macroalgae are becoming a dominant benthic component on Caribbean coral reefs, with increased abundance and frequency across all reef zones. Over the past two decades, different macroalgae like Lobophora variegata (Lamouroux) Womersley ex E.C. Oliveira 1977 (Dictyotales, Dictyotaceae, Fig.1) have proliferated in the reefs of Curaçao, Caribbean. However, the ecological implications of these expansions and the role of these algae as a living substratum to other organisms are poorly known. The present study investigates epiphytic algal communities grown on different macroalgal species along two vertical transects (B0, Pisc) running from shallow to deep reefs (6 to 40 m water depth, Fig.2). The findings show that these macroalgae support high diverse (> 150 spp.) and complex epiphytic communities (Fig.3-6). 1 cm Fig.1 Lobophora variegata Fig.3: Mean number (± ...

Anthropogenic nutrient loading to coastal waters has increased producer biomass, leading to more ... more Anthropogenic nutrient loading to coastal waters has increased producer biomass, leading to more frequent hypoxic events particularly in estuarine systems. To examine how eutrophication and hypoxia might alter consumer assemblages, we surveyed benthic communities in 2 subestuaries of Waquoit Bay, Massachusetts, representing a eutrophic-hypoxic regime and an oligotrophic-oxic regime. The number of consumer species and abundance of organisms were lower in the eutrophic estuary. In particular, there were fewer primary consumers, mainly small crustaceans. These differences in consumer community structure also alter trophic interactions. To examine changes in food web structure that might result from lower prey abundance, we sampled organisms from the 2 sub-estuaries and determined their trophic relationships based on nitrogen stable isotope ratios. Reduced numbers of primary consumers, and hence lower prey availability, led to changes in food web linkages. Specifically, omnivores shifted their diets from an omnivorous diet that is mainly carnivorous in the oligotrophic estuary to feeding mainly as herbivores in the eutrophic estuary, where prey were scarce and macroalgae were abundant. These shifts in trophic structure may have consequences for higher trophic levels.

Planta, 2014

nutrient conditions and lowest when phosphate was limiting. In general, we found that enzymatic r... more nutrient conditions and lowest when phosphate was limiting. In general, we found that enzymatic responses were strongly influenced by nutrient availability, indicating its important role in dictating the local responses of the calcifying primary producer H. opuntia to ocean acidification.

Marine Environmental Research, 2010

Please cite this article as: Olsen, Y.S., Fox, S.E., Kinney, E.L., Teichberg, M., Valiela, I., Di... more Please cite this article as: Olsen, Y.S., Fox, S.E., Kinney, E.L., Teichberg, M., Valiela, I., Differences in urbanization and degree of marine influence are reflected in δ 13 C and δ 15 N of producers and consumers in seagrass habitats of

Marine Ecology Progress Series, 2006

The fact that land-derived sources of nutrients promote eutrophication in the receiving coastal w... more The fact that land-derived sources of nutrients promote eutrophication in the receiving coastal waters implies coupling between land and marine environments. Increasing nitrogen inputs in the estuaries are followed by major shifts in biota composition and abundances. In the present paper we used N and C isotopic ratios to analyze the coupling of benthic and pelagic components of food webs to estuaries receiving different N loads from their watersheds. We found that primary producers, benthic taxa, and fishes were coupled to the watersheds and estuaries where they were collected. In contrast, zooplankton was uncoupled. Primary consumers and predators feeding on benthic prey within the estuaries were also coupled to the watershed and estuaries, but predators feeding on zooplankton were not. We hypothesized that short water residence time in these estuaries uncoupled plankton from terrestrial influence. Stable isotopic measurements of N in producers, consumers, POM, and sediment in different estuaries of Waquoit Bay, Massachusetts, USA, demonstrate a consistent link between land-use on contributing watersheds and the isotopic ratio in all the benthic components and food webs. The remarkably consistent link suggests that the benthos was tightly coupled to land-derived inputs, and that these components, particularly macrophytes, could be good indicators for monitoring increases in land-derived N inputs. Our results showed that stable isotopes of N and C have the potential for use in basic research and applied monitoring, but need to be applied considering the features of estuaries that might couple or uncouple organisms regarding dependency on land, such as hydrodynamic exchanges.

Marine Ecology Progress Series, 2011

Marine Ecology Progress Series, 2008

Increased nutrient inputs to temperate coastal waters have led to increased occurrences of macroa... more Increased nutrient inputs to temperate coastal waters have led to increased occurrences of macroalgal blooms worldwide. To identify nutrients that are limiting to macroalgae and to determine whether different forms of these nutrients and long-term ambient nutrient conditions affect macroalgal response, we used in situ enrichment methods and tested the response of 2 bloom-forming species of macroalgae, Ulva lactuca and Gracilaria tikvahiae, from shallow estuaries of Waquoit Bay, Massachusetts, USA, that receive different land-derived N inputs. We enriched caged macroalgal fronds with nitrate, ammonium, phosphate, and N + P combinations, and measured growth, nutrient content, and δ 15 N signatures of fronds after 2 wk of incubation. In these estuaries, P did not limit growth, however, the 2 species differed in growth response to N additions. Growth of U. lactuca was greater in Childs River (CR), the estuary with higher nitrate inputs, than in Sage Lot Pond (SLP); growth in SLP increased with nitrate and ammonium enrichment. In contrast, growth of G. tikvahiae was greater in SLP than in CR, but had no growth response to N enrichment in either site. C and N contents differed initially between species and sites, and after nutrient enrichment. Final tissue % N increased and C:N decreased after nitrate and ammonium enrichment. δ 15 N values of the macroalgae demonstrated uptake of the experimental fertilizers, and a higher affinity and faster turnover of internal N pools with ammonium than nitrate enrichment in both species. We suggest that U. lactuca blooms in areas with both high nitrate and ammonium water column concentrations, and is more N-limited in oligotrophic waters where DIN levels are too low to sustain high growth rates. G. tikvahiae has a greater N storage capacity than U. lactuca, which may allow it to grow in less nutrientrich waters.

Marine Ecology Progress …, 2011