A5016917436- Marine Biology and Ecology Research
- Marine and coastal ecosystems
- Isotope Analysis in Ecology
- Marine Bivalve and Aquaculture Studies
- Geology and Paleoclimatology Research
- Coastal wetland ecosystem dynamics
- Marine and coastal plant biology
- Marine and fisheries research
- Soil and Water Nutrient Dynamics
- Potato Plant Research
- Aquatic Invertebrate Ecology and Behavior
- Methane Hydrates and Related Phenomena
- Growth and nutrition in plants
- Irrigation Practices and Water Management
- Wastewater Treatment and Nitrogen Removal
- Environmental Toxicology and Ecotoxicology
- Aquaculture Nutrition and Growth
- Ocean Acidification Effects and Responses
- Freshwater macroinvertebrate diversity and ecology
- Sustainability and Ecological Systems Analysis
- Fish Ecology and Management Studies
- Echinoderm biology and ecology
- Coral and Marine Ecosystems Studies
- Berry genetics and cultivation research
- Coastal and Marine Management
University of Otago
2015-2024
University of Cape Town
2015-2024
Stockholm University
2001-2010
Virginia Cooperative Extension
1990-2005
Virginia Tech
1990-2005
In recent decades, the land-ocean aquatic continuum, commonly defined as interface, or transition zone, between terrestrial ecosystems and open ocean, has undergone dramatic changes. On-going work stressed importance of treating Aquatic Critical Zones (ACZs) a sensitive system needing intensive investigation. Here, we discuss fjords an ACZ in context sedimentological, geochemical, climatic impacts. These diverse physical features are key controlling sources, transport, burial organic matter...
Background Bioturbators affect multiple biogeochemical interactions and have been suggested as suitable candidates to mitigate organic matter loading in marine sediments. However, predicting the effects of bioturbators at an ecosystem level can be difficult due their complex positive negative with microbial community. Methodology/Principal Findings We quantified deposit-feeding sea cucumbers on benthic algal biomass (microphytobenthos, MPB), bacterial abundance, sediment–seawater exchange...
Nutrient discharges from sewage treatment plants can contribute significantly to coastal and estuarine eutrophication. To counter anthropogenic nitrogen (N) loads in a Baltic Sea embayment, improved (∼85%) N removal was implemented tertiary sewage‐treatment plant. This study used stable‐isotope ratios (δ 15 N) attached brown macroalgae, Fucus vesiculosus , map the change spatial extent of influence sewage‐derived N. Elevated content δ values = 8–9‰) suggest that still traceable algal tissues...
Sedimentary records of organic matter inputs (stable nitrogen isotopes [δ 15 N], [N], and carbon [C] content), phytoplankton abundance (pigments, stable 13 C]), community composition (pigments) were used to reconstruct the history pathway water‐quality degradation in a Swedish Baltic coastal bay. Changes nutrient sources cycling began 1800s, but eutrophication intensified only after 1950s, coincident with agricultural practices. Specifically, sedimentary N C content doubled, δ increased,...
Estuaries are highly productive ecosystems that can export organic matter to coastal seas (the 'outwelling hypothesis'). However the role of this food resource subsidy on ecosystem functioning has not been examined.We investigated influence estuarine primary production as a and estuaries biodiversity in mollusk-dominated sediment communities. Stable isotope values (δ(13)C, δ(15)N) demonstrated was exported adjacent coast contributed secondary up 4 km from estuary mouth. Further, signatures...
Abstract Nutrient subsidies across ecotone boundaries can enhance productivity in the recipient ecosystem, especially if nutrients are transferred from a nutrient rich to an oligotrophic ecosystem. This study demonstrates that seabird islands assimilated by endosymbionts corals on fringing reefs and growth of dominant reef-building species, Acropora formosa . Nitrogen stable isotope ratios (δ 15 N) zooxanthellae were enriched near colonies decreased linearly with distance land, suggesting...
Marine ecosystems are prone to tipping points, particularly in coastal zones where dramatic changes associated with interactions between cumulative stressors (e.g., shellfish harvesting, eutrophication and sediment inputs) ecosystem functions. A common feature of many degraded estuaries is elevated turbidity that reduces incident light the seafloor, resulting from multiple factors including loading, sea-level rise increased water column algal biomass. To determine whether effects may result...
Anthropogenic nitrogen (N) often causes coastal eutrophication, yet little is known about the fate and retention of effluent N in waters and, hence, system’s ability to assimilate excess loads. We used spatial distribution stable isotope ratios algal pigments sedimentary organic matter from a Baltic bay receiving tertiary‐treated evaluate extent effects role nearshore marine environments as sinks anthropogenic N. Surface sediments (0–2 cm 2–4 cm) exhibited pronounced gradient δ 15 N, with...
Thresholds profoundly affect our understanding and management of ecosystem dynamics, but we have yet to develop practical techniques assess the risk that thresholds will be crossed. Combining ecological knowledge critical system interdependencies with a large-scale experiment, tested for breaks in interaction network identify threshold potential real-world dynamics. Our experiment bivalves Macomona liliana Austrovenus stutchburyi on marine sandflats New Zealand demonstrated reductions...
Abstract Transport of particles plays a major role in redistributing organic carbon (OC) along coastal regions. In particular, the global importance fjords as sites burial has recently been shown to be even more important than previously thought. this study, we used six surface sediments from Fiordland, New Zealand, investigate transport and OC based on density fractionation. Bulk, biomarker, principle component analysis were applied fractions with ranges <1.6, 1.6–2.0, 2.0–2.5, >2.5 g...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 243:67-82 (2002) - doi:10.3354/meps243067 Effects of sewage-derived nutrients on an estuarine macrobenthic community Candida Savage*, Ragnar Elmgren, Ulf Larsson Department Systems Ecology, Stockholm University, 106 91 Stockholm, Sweden *E-mail: candida@system.ecology.su.se ABSTRACT: Eutrophication is one...
Long‐term (1977–2000) ecological biomass data for total phytoplankton, diatoms, and cyanobacteria, based on plankton samples from Himmerfjärden Bay (Baltic proper), were compared to the historical sediment record using diagnostic plant pigment biomarkers. Radionuclides ( 210 Pb 137 Cs) used determine chronology, sedimentation, carbon burial rate. Despite high resolution sampling, crust‐freeze of layers representing annual varves, no significant correlations between pigments preserved in...
Abstract A model to estimate nitrogen loads from coastal catchments New Zealand estuaries is presented. The Sub‐Catchment Estuary Nitrogen Yield (SCENY) estimates total inputs atmospheric deposition, fertiliser application, and biological fixation for with different land use practices. losses in the vadose zone aquifers were assessed, net yield that enters was quantified. applied 13 sub‐catchments South Island, which encompass 0–91% agricultural use. yields study ranged 0.6 kg N ha−1 yr−1...
Abstract Fjords have recently been recognized as “hot spots” of carbon burial. In this study, we investigated organic (OC) and biomarker radiocarbon values in fjord sediments from New Zealand. Our results showed that OC was mostly modern with the most aged middle reaches fjords, likely related to hydrodynamic sorting inputs along adjacent slopes. Radiocarbon ages sedimentary increased north‐to‐south, consistent Fiordland regional gradients lower slopes less rainfall. suggested lignin...