Research Projects 2012-2014
Rhode Island Sea Grant’s research investments for the 2012-2014 omnibus period ventured into new venues of concerning fish and shellfish aquaculture, as well as build upon ongoing efforts bringing together social and climate change sciences. Rhode Island Sea Grant will also continue investment in the critical issue of nutrient dynamics and its implications for ecosystem-based management in Narragansett Bay.
Does certified sustainable seafood impact protect fisheries stock and market value?
Certification of a fishery by the Marine Stewardship Council (MSC) has been assumed to improve stock status, lending to the creation of a sustainable fishery. Seafood certification programs have been assumed to improve stock status and build sustainable fishery practices that better serve fishermen and market demand. There has been ongoing controversy, however, on whether current certification standards actually yield assumed ecological and economical. These assumed benefits of seafood certification have never been verified by thorough scientific examination to adequately justify effectiveness of such programs.
Sea Grant funded Jeremy Collie, professor and researcher at the University of Rhode Island’s Graduate School of Oceanography, to conduct research examining the effects of certification by the Marine Stewardship Council (MSC), a certification used by most fisheries, on fishery stock status and the economic/market benefits to fishermen and the fishing industry over a 10-year span.
RESULTS: MSC certification was shown to improve stocks for both Atlantic herring and hake, but only the Atlantic herring displayed a difference statistically significant. Initial research findings also verified assumptions of decreased fishing mortality post MSC certification.
Expensive and malnourishing fishmeal have been some barriers to expansive fin fish aquaculture efforts.
There has been a strong effort in New England to develop groundfish aquaculture as a means to provide a safe, sustainable source of protein to supplement wild harvests in meeting market demands for a growing population. Summer flounder, a highly desirable groundfish in New England, has struggled in aquaculture efforts due to a lack of economical and sustainable feed source coupled with crippling disease outbreaks in culture facilities, which greatly inhibits groundfish aquaculture capacity for summer flounder in the region.
Sea Grant funded Marta Gomez-Chiarri, researcher and professor at the University of Rhode Island, to conduct research on the use of soy protein, a sustainable and economical resource, in fishmeal as an alternative to supplement feed for summer flounder that could encourage aquaculture efforts for this species. Gomez-Chiarri’s research will also look into previous findings that indicate soy protein’s potential in decreasing disease susceptibility in summer flounder stocks.
RESULTS: Slower growth rates and decreased mortality rates from bacterial disease were observed in summer flounder stock treated with soy-based feed compared to socks fed traditional fishmeal products. These initial findings have promoted continued research on quantifying bacterial resistance and exploring additives to improve growth rates related to soy-based feed, as well as assessing economic benefits of a soy-based alternative.
Controlling water flow patterns may help oysters, and even clams, grow faster.
Sea Grant funded-researcher Dale Leavitt (Roger Williams University) will be focusing on the use of upwellers in shellfish aquaculture systems to determine if altering the amount, timing, and pattern of water flow through the systems will speed oyster and hard clam growth to market size. An anticipated benefit is a reduction in the energy used when flow is manipulated, reducing costs and improving the economic viability of shellfish production in hatchery-based systems.
While oysters are currently the major aquaculture crop in Rhode Island, mussel aquaculture has huge potential.
The harvest window for mussel farm operations in Rhode Island is currently between September and December due to lack of seed supply, making it difficult for operations to meet premium summer markets. Rhode Island Sea Grant funded Scott Lindell of the Marine Biological Laboratory to conduct research that would investigate the culture of mussel seed in an aquaculture setting to assess the feasibility of extending mussel harvests in Narragansett Bay.
RESULTS: Initial trials with mussel seed production proved encouraging, showing the potential to allow expansion of the seed-to-harvest cycle beyond the September to December timeframe. Based on these preliminary yet encouraging results, a Saltonstall-Kennedy grant was applied for, and awarded, in September 2014. Work will continue on a methodology to produce reliable seed stock for a growing Rhode Island mussel aquaculture industry.Sea Grant funded-researcher Scott Lindell (Marine Biological Laboratory) will be conducting biological and ecological experiments to define mechanisms by which mussel aquaculture can most effectively be developed as an industry in Narragansett Bay.
A more comprehensive nutrient criteria for Narragansett Bay is needed for water quality management.
Sea Grant is supporting four projects to assist in the develop of a more comprehensive nutrient criteria for Narragansett Bay to improve water quality management.
– Mircobes and Nutrient Input –
Efforts are underway to reduce nitrogen loading to Narragansett Bay by 50%, resulting in an overall 30% reduction in total nitrogen input. Resource managers anticipate an associated improvement in the extent and severity of hypoxic waters in upper Narragansett Bay. Hypoxic conditions break the nitrogen cycle and promotes the occurrence of sulfur using microorganisms, which further disrupts the nitrogen cycle, exasperating degraded ecological conditions. Documentation of actual changes should be undertaken to improve understanding of linkages between nutrient reduction and change in the bay ecosystem. Rhode Island Sea Grant funded URI researcher Bethany Jenkins to study the microbial community and its interactions with the nitrogen cycle as it relates to nutrient reduction program onset, and to record the changes observed so as to improve understanding of the Bay ecosystem.
RESULTS: Unexpected feedback loops in the nitrogen cycle in Narragansett Bay were found. As hypoxic conditions occurred, bacteria with genetic markers similar to those of sulfur bacteria were noted, and these bacteria cycle nitrogen back into the system rather than remove it in a gaseous phase. It is possible that despite nutrient reduction efforts in Narragansett Bay, increased hypoxia resulting from warming waters could result in a lesser reduction than anticipated, and that hypoxia may not be alleviated as expected.
– Eco-functioning of Narragansett Bay –
Management of wastewater inputs to Narragansett Bay are being controlled so that a 50% to 70% reduction in nutrient loading is achieved. The expected result is that hypoxic conditions will be lessened as eutrophication is reduced. It is unknown however if other ecosystem responses may occur, in particular if phytoplankton concentrations, the primary link in the food web utilizing nutrients for growth, will be reduced and in essence, “starve” the bay. Rhode Island Sea Grant funded URI research Theodore Smayda to study historical trends in the dominant Narragansett Bay phytoplankton community, to compare this to contemporary patterns as nutrient loadings to the bay are reduced, and to consider the impacts to the phytoplankton community as well as to the Narragansett Bay food web.
RESULTS: Observation of historical trends in the Narragansett Bay phytoplankton community show an overall reduction in chlorophyll concentrations since the 1990s. A portion of this reduction is likely due to increased water clarity resulting from improved solids retention in wastewater treatment protocols, which due to increase light levels, reduces phytoplankton chlorophyll by 15-20% (e.g., they produce less in stronger light). A reduction in actual phytoplankton cell counts—which reflects the actual abundance of phytoplankton and not just the chlorophyll they contain—is also observed, and may be a result of reduced nutrient availability.
Rhode Island Sea Grant also funded researcher Rebecca Robinson (URI ) to identify various isotopes of nitrogen, and find out if they could be used as tracers to help identify sources of nitrogen and to see if it were possible to measure impacts to primary production, based on isotopic signatures, from the initiation of tertiary wastewater treatment.
RESULTS: Wastewater nitrogen isotopic composition increased to approximately 18% for d15N-NO3 while natural oceanic water generally is 5–6 percent. This discrepancy should allow for a more robust accounting of the sources of nitrogen to Narragansett Bay. However, higher nitrate concentrations were found in Narragansett Bay after tertiary treatment was initiated, which was not expected. Outside of the Providence River area, oceanic water sources of nitrogen were dominant, and so it does not appear that nitrogen reductions in upper bay sources will result in reduced primary production in the upper bay, and will likely not lead to improved hypoxic conditions. Internal cycling of nitrogen in the bay is more complicated than anticipated, and is confusing the ability to read nitrogen isotopic signals as originally imagined.
– Phytoplankton as Nutrient Measures –
Phytoplankton, the fuel for the Narragansett Bay ecosystem, is experiencing a decrease in abundance as well as a shift in the timing and length of the winter-spring bloom. Changing climatic conditions have been implicated as a likely cause of these changes, but there is no evidence to back the implication. Rhode Island Sea Grant-funded researcher Tatiana Rynearson investigated shifts in the Skeletonema phytoplankton complex, the dominant phytoplankton in Narragansett Bay, to see if the changes are linked to climate.
RESULTS: Rynearson developed new genetic-based, molecular level technologies for identifying the different species of Skeletonema inhabiting Narragansett Bay. Seven separate species have been identified, and each species appears to bloom in different parts of the year. The development of these new tools will allow researchers track growth patterns of each species annually, and match this to environmental conditions to determine if and how climatic conditions are influencing phytoplankton growth.
– New tools to track nutrient movements –
Hydrodynamic models are a useful tool for resource managers engaged in water quality management efforts to better understand circulation dynamics of a system. The more refined a model is the more useful and realistic it is for management purposes. Building high resolution, 3-dimensional scale models can only be resolved with high quality local data. Rhode Island Sea Grant funded URI research Christopher Kincaid to collect further data in Narragansett Bay that would allow his team of modelers to expand an existing model into a high resolution simulation tool useful for management.
RESULTS: The R.I. Dept. of Environmental Management and the Narragansett Bay Commission are utilizing the updated model to understand and resolve issues related to hypoxic conditions in upper Narragansett Bay. The model shows that previous estimates of water movement were highly inaccurate, and that the areas suffering the worst hypoxia experience sluggish circulation, promoting retention of nutrients and exasperating hypoxia. Now that the critical role circulation is playing in the causation of hypoxic events in the upper bay, nutrient inputs and circulatory patterns are being studied to see if changes to wastewater discharges can be altered to minimize the onset, duration, and distribution of hypoxia. The model is also being used by other researchers who are applying it to better understand the transport of larval shellfish throughout Narragansett Bay, and to apply this understanding to help manage shellfish harvesting and to consider the placement of spawning and/or larval settlement sanctuaries in the bay. Outcomes of these modeling efforts are being incorporated into the Rhode Island Shellfish Management Plan. The model is also being used by the non-profit Save Bristol Harbor, who is using the model to better understand circulation in the harbor and apply it at a municipal level to better manage moorings, bathing beaches, and natural resources.
Understanding behaviors and motivators to aid in climate change adaptation
The third and final year of the Climate Change Collaborative, led by Pamela Rubinoff (URI Coastal Resources Center), investigated changing human behaviors for adaptation to the impacts brought on by a changing climate, such as sea level rise and increased storminess.
The project team is adopted a methodology used to change behaviors that reduce cancer rates through smoking cessation, following a five-step process moving from acknowledgement of a problem to finding solutions.
The intention of this research is to build awareness of climate change through an interdisciplinary approach that utilizes expertise across various scientific fields and to encourage behavioral change in coastal communities through adaptation and mitigation to prepare for anticipated changes caused by a changing climate.
Investigating Climate Adaptation Drivers through Societal and Economic Tradeoffs
In order to improve understanding of the tradeoffs to be considered—both societal and economic—in the decision-making process concerning climate change adaptation, Rhode Island Sea Grant and other Sea Grant programs in the Northeast through the Northeast Sea Grant Consortium will fund two regional projects that address such tradeoffs.
– Marine Spatial Planning-
Porter Hoagland (Woods Hole Oceanographic Institution Marine Policy Center) will explore the regional economic base and will define and evaluate tradeoffs involved in the rapidly evolving field of coastal marine spatial planning.
Robert Johnston (Clark University) will examine costs and benefits of climate adaptation strategies, and their impacts on ecosystem services and ecosystem resilience.
These projects define behavioral change models under development by adding another layer of depth and understanding in the decision/choice processes.
A Changing Climate May Interfere with Current Septic System Designs
Due to wetter weather conditions and rising sea level as a result of changing climate, nitrogen inputs into the groundwater from septic systems may increase and impact coastal lagoon ecosystems, specifically in Rhode Island’s south shore, as well as the functioning of onsite wastewater treatment systems. Conventional systems in coastal zones are becoming inadequate to properly treat wastewater due changing climate conditions, primarily seen as saltwater inundation from rising sea levels and increased temperatures that interfere with the biochemical reactivity of surface soils necessary for wastewater treatment. Coastal ecosystems, particularly salt ponds and lagoons, are sensitive environments highly vulnerable to an influx of poorly treated wastewater that pose a myriad of problems to the function of these critical habitats.
Sea Grant-funded researcher George Loomis (URI Cooperative Extension)—the expert who helped define the existing septic system management regime for Rhode Island’s lagoon ecosystems—to develop soil mesocosms for new experiments looking at the effects of various changing climate scenarios on soil aeration and texture, soil microbial ecology, nitrogen dynamics, and overall soil performance of onsite wastewater treatment in low-lying coastal soils.
RESULTS: Researchers are recommending that state and federal officials rethink the regulations for the installation and management of home septic systems, especially in the coastal zone, in light of research they conducted that demonstrated that warming temperatures and rising sea levels will reduce the effectiveness of conventional septic systems.
Findings include that one-foot increase in the height of the water table due to sea level rise and a 5 degree centigrade increase in air temperature would reduce a septic system’s ability to filter out phosphorous and nitrogen before it reaches the groundwater and nominally affect bacteria and carbon removal.
For experiments looking at the effectiveness of systems under current climate conditions, almost all bacteria, phosphorous and carbon were filtered from the wastewater before it reached the groundwater, and between 5 and 12 percent of the nitrogen was removed. But when warmer conditions and a rise of the water table were simulated, contaminant removal declined across the board.
“When sea level rises, it makes the water table rise, and that reduces the distance between the groundwater and the drainfield,” Amador explained. “It means there is less of an opportunity for the soil to treat the wastewater before it reaches the groundwater.”
Septic systems located in inland areas not affected by sea level rise will be less impacted, although the expected increase in the frequency and severity of rainstorms will occasionally raise the water table and temporarily decrease the effectiveness of septic systems. And in areas where climate change will bring increasing drought conditions, it is predicted that water conservation efforts will result in a more concentrated wastewater effluent that will be more difficult for soil to treat.
Researchers recommend upgrades to existing systems in at-risk areas and modify requirements for the design and installation of new systems.
Recalibrating Sediment Flux Model to Predict Impacts of Changes in Narragansett Bay
Researcher Damian Brady (University of Maine) will be taking a sediment flux model developed in the 1980s, and still in use today for managing nutrient loading to waterbodies, and calibrating it for use in Narragansett Bay.
Brady will use long-term datasets for the Bay, as well as new data collected by researchers funded by Rhode Island Sea Grant during its 2010-2012 omnibus (Fulweiler, Nixon, Rich) to improve the model for use in predicting impacts to Narragansett Bay based upon various nutrient reduction and climate change scenarios. Outputs of the model will prove useful to resource managers for setting nutrient control guidance in the face of changing climate.
Research Looks at Potential to Repurpose Scallop Waste for Fish Food
Sea scallops are harvested for their succulent adductor muscles, with the remainder of the organism, the viscera, disposed as waste. The ability to utilize this waste product as a fishmeal replacement, or as a supplementary feed, could reduce the waste stream, remove costs for disposal, and provide added value for scallop harvesters, making them more profitable. Rhode Island Sea Grant funded nutritional scientist Chong Lee (URI) to test the use of sea scallop viscera as a feed product for European sea bass, a highly cultured species that is a major consumer of fishmeal products.
RESULTS: Sea scallop viscera-based feeds were found to outperform traditional fish feed products in terms of improved fish weight gain, improved feed-to-fish conversion ratios, and were found to be more favored by fish as a food source.