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Full-Text Articles in Aquaculture and Fisheries

Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard Oct 2017

Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard

VIMS Articles

Parasitism is a fundamental ecological interaction. Yet we understand relatively little about the ecological role of parasites compared to the role of free-living organisms. Bottom-up theory predicts that resource enhancement will increase the abundance and biomass of free-living organisms. Similarly, parasite abundance and biomass should increase in an ecosystem with resource enhancement. We tested this hypothesis in a landscape-level experiment in which salt marshes (60,000 m2 each) received elevated nutrient concentrations via flooding tidal waters for 11 yr to mimic eutrophication. Nutrient enrichment elevated the densities of the talitrid amphipod, Orchestia grillus, and the density and biomass of its ...


Sea Level Rise May Increase Extinction Risk Of A Saltmarsh Ontogenetic Habitat Specialist, David S. Johnson, Bethany L. Williams Aug 2017

Sea Level Rise May Increase Extinction Risk Of A Saltmarsh Ontogenetic Habitat Specialist, David S. Johnson, Bethany L. Williams

VIMS Articles

Specialist species are more vulnerable to environmental change than generalist species. For species with ontogenetic niche shifts, specialization may occur at a particular life stage making those stages more susceptible to environmental change. In the salt marshes in the northeast U.S., accelerated sea level rise is shifting vegetation patterns from flood-intolerant species such as Spartina patens to the flood-tolerant Spartina alterniflora. We tested the potential impact of this change on the coffee bean snail, Melampus bidentatus, a numerically dominant benthic invertebrate with an ontogenetic niche shift. From a survey of eight marshes throughout the northeast U.S., small snails ...


Asynchrony Among Local Communities Stabilises Ecosystem Function Of Metacommunities, Kr Wilcox, At Tredennick, Se Koerner, E Grman, Lm Hallett, Ds Johnson, Et Al. Jan 2017

Asynchrony Among Local Communities Stabilises Ecosystem Function Of Metacommunities, Kr Wilcox, At Tredennick, Se Koerner, E Grman, Lm Hallett, Ds Johnson, Et Al.

VIMS Articles

Temporal stability of ecosystem functioning increases the predictability and reliability of ecosystem services, and understanding the drivers of stability across spatial scales is important for land management and policy decisions. We used species-level abundance data from 62 plant communities across five continents to assess mechanisms of temporal stability across spatial scales. We assessed how asynchrony (i.e. different units responding dissimilarly through time) of species and local communities stabilised metacommunity ecosystem function. Asynchrony of species increased stability of local communities, and asynchrony among local communities enhanced metacommunity stability by a wide range of magnitudes (1-315%); this range was positively correlated ...


Abundance And Local-Scale Processes Contribute To Multi-Phyla Gradients In Global Marine Diversity, Gj Edgar, Tj Alexander, Js Lefcheck, Ae Bates, Sj Kininmonth, Et Al. Jan 2017

Abundance And Local-Scale Processes Contribute To Multi-Phyla Gradients In Global Marine Diversity, Gj Edgar, Tj Alexander, Js Lefcheck, Ae Bates, Sj Kininmonth, Et Al.

VIMS Articles

Among themost enduring ecological challenges is an integrated theory explaining the latitudinal biodiversity gradient, including discrepancies observed at different spatial scales. Analysis of Reef Life Survey data for 4127 marine species at 2406 coral and rocky sites worldwide confirms that the total ecoregion richness peaks in low latitudes, near +15 degrees N and -15 degrees S. However, although richness at survey sites is maximal near the equator for vertebrates, it peaks at high latitudes for large mobile invertebrates. Site richness for different groups is dependent on abundance, which is in turn correlated with temperature for fishes and nutrients for macroinvertebrates ...


Shelled Pteropods In Peril: Assessing Vulnerability In A High Co2 Ocean, C Manno, N Bednarsek, Ga Tarling, Vl Peck, S Comeau, Patricia S. Thibodeau, Et Al. Jan 2017

Shelled Pteropods In Peril: Assessing Vulnerability In A High Co2 Ocean, C Manno, N Bednarsek, Ga Tarling, Vl Peck, S Comeau, Patricia S. Thibodeau, Et Al.

VIMS Articles

The impact of anthropogenic ocean acidification (OA) on marine ecosystems is a vital concern facing marine scientists and managers of ocean resources. Euthecosomatous pteropods (holoplanktonic gastropods) represent an excellent sentinel for indicating exposure to anthropogenic OA because of the sensitivity of their aragonite shells to the OA conditions less favorable for calcification. However, an integration of observations, experiments and modelling efforts is needed to make accurate predictions of how these organisms will respond to future changes to their environment. Our understanding of the underlying organismal biology and life history is far from complete and must be improved if we are ...


Lipid Consumption In Coral Larvae Differs Among Sites: A Consideration Of Environmental History In A Global Ocean Change Scenario, Eb Rivest, Cs Chen, Ty Fan, Hh Li, Ge Hofmann Jan 2017

Lipid Consumption In Coral Larvae Differs Among Sites: A Consideration Of Environmental History In A Global Ocean Change Scenario, Eb Rivest, Cs Chen, Ty Fan, Hh Li, Ge Hofmann

VIMS Articles

The success of early life-history stages is an environmentally sensitive bottleneck for many marine invertebrates. Responses of larvae to environmental stress may vary due to differences in maternal investment of energy stores and acclimatization/adaptation of a population to local environmental conditions. In this study, we compared two populations from sites with different environmental regimes (Moorea and Taiwan). We assessed the responses of Pocillopora damicornis larvae to two future co-occurring environmental stressors: elevated temperature and ocean acidification. Larvae from Taiwan were more sensitive to temperature, producing fewer energy-storage lipids under high temperature. In general, planulae in Moorea and Taiwan responded ...


Tropical Dead Zones And Mass Mortalities On Coral Reefs, Ah Altieri, Sb Harrison, J Seemann, R Collin, Rj Diaz, N Knowlton Jan 2017

Tropical Dead Zones And Mass Mortalities On Coral Reefs, Ah Altieri, Sb Harrison, J Seemann, R Collin, Rj Diaz, N Knowlton

VIMS Articles

Degradation of coastal water quality in the form of low dissolved oxygen levels (hypoxia) can harm biodiversity, ecosystem function, and human wellbeing. Extreme hypoxic conditions along the coast, leading to what are often referred to as "dead zones," are known primarily from temperate regions. However, little is known about the potential threat of hypoxia in the tropics, even though the known risk factors, including eutrophication and elevated temperatures, are common. Here we document an unprecedented hypoxic event on the Caribbean coast of Panama and assess the risk of dead zones to coral reefs worldwide. The event caused coral bleaching and ...


Ghost Of Invasion Past: Legacy Effects On Community Disassembly Following Eradication Of An Invasive Ecosystem Engineer, Pl Reynolds, J Glanz, S Yang, C Hann, J Couture, E Grosholz Jan 2017

Ghost Of Invasion Past: Legacy Effects On Community Disassembly Following Eradication Of An Invasive Ecosystem Engineer, Pl Reynolds, J Glanz, S Yang, C Hann, J Couture, E Grosholz

VIMS Articles

By changing ecosystem processes and altering the physical landscape, invasive ecosystem engineers can have substantial impacts on ecosystem functions and human economies and may facilitate other non-native species. Eradication programs in terrestrial and aquatic systems aim to reverse the impacts of invasive species and return the system to its pre-invasion conditions. Despite an extensive focus on the impacts of both native and non-native ecosystem engineers, the consequences of removing invasive ecosystem engineers, particularly in coastal ecosystems, are largely unknown. In this study, we quantified changes in a benthic community following the eradication of the invasive ecosystem engineer, hybrid cordgrass Spartina ...


Consumer Versus Resource Control And The Importance Of Habitat Heterogeneity For Estuarine Bivalves, Rd Seitz, Rn Lipcius, Ah Hines Jan 2017

Consumer Versus Resource Control And The Importance Of Habitat Heterogeneity For Estuarine Bivalves, Rd Seitz, Rn Lipcius, Ah Hines

VIMS Articles

The relative influence of consumers (top down) and resources (bottom up) on the distribution and abundance of organisms remains a key question in ecology. We examined the relationships between consumer and resource variables along a productivity gradient for a dominant predator-prey interaction in a marine soft-sediment system. We 1) quantified density and size of the clam Macoma balthica (prey species) in six replicate sites at each of four habitat types (shallow mud, deep mud, muddy sand and detrital mud) in the Rhode River, Chesapeake Bay. We selected one habitat type of high food availability and clam density (shallow mud) and ...


Carbon Budget Of A Shallow, Lagoonal Estuary: Transformations And Source-Sink Dynamics Along The River-Estuary-Ocean Continuum, Jr Crosswell, Ic Anderson, Jw Stanhope, B Van Dam, Mj Brush, Et Al. Jan 2017

Carbon Budget Of A Shallow, Lagoonal Estuary: Transformations And Source-Sink Dynamics Along The River-Estuary-Ocean Continuum, Jr Crosswell, Ic Anderson, Jw Stanhope, B Van Dam, Mj Brush, Et Al.

VIMS Articles

A comprehensive carbon budget was constructed to quantify carbon flows through the freshwater-marine continuum of a temperate, microtidal estuary. We performed coordinated measurements of dissolved inorganic carbon and total organic carbon fluxes to resolve spatial variability between and along the channel and shoals and diel variability across the entire estuary for 2 yr. Net ecosystem metabolism (NEM) was the most significant control on carbon flow within estuary regions. However, metabolic rates were spatially coupled such that counteracting fluxes across the channel-shoal gradient or along the river-ocean gradient resulted in system-wide NEM that was closely in balance (-3.0 +/- 3.3 ...


Linking The Abundance Of Estuarine Fish And Crustaceans In Nearshore Waters To Shoreline Hardening And Land Cover, Ms Kornis, D Breitburg, R Balouskus, Dm Bilkovic, La Davias, Rd Seitz, Et Al. Jan 2017

Linking The Abundance Of Estuarine Fish And Crustaceans In Nearshore Waters To Shoreline Hardening And Land Cover, Ms Kornis, D Breitburg, R Balouskus, Dm Bilkovic, La Davias, Rd Seitz, Et Al.

VIMS Articles

Human alteration of land cover (e.g., urban and agricultural land use) and shoreline hardening (e.g., bulkheading and rip rap revetment) are intensifying due to increasing human populations and sea level rise. Fishes and crustaceans that are ecologically and economically valuable to coastal systems may be affected by these changes, but direct links between these stressors and faunal populations have been elusive at large spatial scales. We examined nearshore abundance patterns of 15 common taxa across gradients of urban and agricultural land cover as well as wetland and hardened shoreline in tributary subestuaries of the Chesapeake Bay and Delaware ...


Spatio-Temporal Development Of Vegetation Die-Off In A Submerging Coastal Marsh, L Schepers, M Kirwan, G Guntenspergen, S Temmerman Jan 2017

Spatio-Temporal Development Of Vegetation Die-Off In A Submerging Coastal Marsh, L Schepers, M Kirwan, G Guntenspergen, S Temmerman

VIMS Articles

In several places around the world, coastal marsh vegetation is converting to open water through the formation of pools. This is concerning, as vegetation die-off is expected to reduce the marshes' capacity to adapt to sea level rise by vegetation-induced sediment accretion. Quantitative analyses of the spatial and temporal development of marsh vegetation die-off are scarce, although these are needed to understand the bio-geomorphic feedback effects of vegetation die-off on flow, erosion, and sedimentation. In this study, we quantified the spatial and temporal development of marsh vegetation die-off with aerial images from 1938 to 2010 in a submerging coastal marsh ...