Multi-trophic Aquaculture: Connecting Research to New Hampshire Ecosystems, Communities and Economies
Michael Chambers, Research Project Engineer, Affiliate Faculty
Hunt Howell, Professor of Zoology
Initial training of fishermen on small scale, integrated multi-trophic aquaculture in New Hampshire
Over the last five years, the commercial fishing fleet in New England has been subjected to increasingly restrictive management measures established to rebuild declining stocks. By design, these measures have limited fishing opportunities and significantly reduced the inshore small vessel fleet. To help support New Hampshire fishermen, an extension program was developed by UNH and N.H. Sea Grant to train fishermen on small scale integrated multi-trophic aquaculture (IMTA) in the Piscataqua River. Regulatory agencies had concern of nutrient input from fish production so a model was designed to measure nutrient uptake from shellfish and seaweed integrated into the growout platform. The model was demonstrated while fishermen were trained “hands on” with the necessary husbandry skills for culturing the three species together. Nutrient extraction, both organic and inorganic, was greater than the input from trout production resulting in additional nitrogen being drawn from the river. The training program provided the fishermen with a new skill set that they could adopt part time or full time. In addition, the IMTA farm created extra income for the fishermen as they traveled to and from their daily fishing grounds.
Commercial fishing has been a vital component of New England's economy for centuries. However, during the last decade an influx of low-cost, imported seafood has displaced domestic seafood in many commercial markets. Recent federal regulations — specifically, the shift to sector management and quota allocations for groundfish — have contributed to a reduction in New Hampshire's total catch and its fleet. This has led fishermen to explore alternatives to increase their profits by reducing the costs of handling, transportation, processing and distribution by out-of-state distribution agents.
Despite efforts to establish and capitalize on alternative, direct-to-consumer markets, direct sales represent only a fraction of the total fish catch in the state and the full market potential and capacity for expansion remains unclear. French and collaborating researchers will examine data from previously conducted consumer surveys to characterize seafood preferences by potential consumers within a half-day-goods-distance of N.H. ports where fishermen unload their catch (approximately 150 miles). As with the consumer data, national data on retailer preferences will be examined to determine what factors retailers, restaurants, fish mongers and other alternative venues consider when purchasing seafood products from their suppliers.
Researchers will geographically delineate the potential market for local, sustainably-caught seafood, characterize demand and preferences by existing market outlets, identify opportunities to develop new alternative markets, and assess the N.H. seafood industry's capacity to capitalize on alternative markets and/or expand traditional markets. In addition, they will identify best practices for tapping into local and regional alternative markets. These results will help the N.H. commercial fishing industry to be better positioned to deal with further regulatory changes and less susceptible to competition by low-cost imports.
Estuarine ecosystems such as Great Bay offer a unique opportunity to investigate the behavior, population dynamics and reproductive potential of commercially and ecologically important species such as the American lobster, Homarus americanus. Previous studies have shown that lobster populations in Great Bay are somewhat unique with respect to their sex ratios, seasonal migrations and movements in response to episodic environmental changes. While some lobsters migrate into and out of the estuary, our recent data suggest that there might also be a resident population of lobsters. The overall goal for this project was to determine if there is a self-sustaining lobster population in the estuary.
We fished a number of standard and modified traps in the estuary from 2012-2014 and captured a number of juvenile lobsters in many locations. These lobsters most likely settled in Great Bay and grew up there because they are too small to travel very far. We also captured some larval lobsters in plankton tows, suggesting they hatched in Great Bay. Finally, we used drifters to estimate the trajectories that larval lobsters would take if they hatched in the estuary, and we found that the currents tended to retain them in the estuary rather than carrying them out into the Gulf of Maine. These data, taken together with earlier data showing that lobsters with eggs remained in the estuary until their eggs hatched, indicate that there is a self-sustaining population of lobsters in the Great Bay Estuary.
As a result of our extensive sampling program we have also documented a large population of green crabs in the estuary, as well as some blue crabs. These data will also be discussed during the presentation.
Precipitous declines in wild populations of river herring species (alewives, Alosa pseudoharengus, and blueback herring, A. aestivalis) have led to increased interest in stock enhancement efforts. Additionally, their popularity as a baitfish among recreational anglers has generated interest in commercial production of these species for marine baitfish markets. In this investigation we developed methods for spawning wild-caught adults during their spawning migration and raising larvae until one year of age. Additionally, a number of salinity tolerance experiments were conducted and river herring were hybridized in captivity. In collaboration with N.H. Fish and Game and the U.S. Fish and Wildlife Service, over 900,000 tetracycline-marked, larval river herring were stocked into the Great Bay Estuary.
The Great Bay of New Hampshire has been classified as nitrogen impaired due to elevated nitrogen loads from its surrounding watershed. Elevated nitrogen loads result from both point and non-point sources associated with intensified suburbanization as well as residual agricultural activity. A large proportion of non-point nitrogen export occurs during storm events due to enhanced mobilization and transport. Yet very little information exists regarding storm event nutrient dynamics due to logistical difficulties of collecting sufficient samples throughout entire storm event hydrographs across seasons. New in situ optical sensor technology is now available that allows continuous nutrient monitoring in streams and rivers, offering the potential to better understand sources and fate of non-point nutrient pollution. The overarching objective of this research is to understand the mechanisms that control N exports from the Lamprey River watershed to the Great Bay over a range of climate/flow conditions and to share this understanding with local land use planners and decision makers to inform possible mitigation strategies for reducing locally generated N inputs. Our approach is to deploy continuous in situ sensors at the Lamprey River USGS gauging station located five km upstream of the Great Bay to monitor nitrogen and organic carbon fluxes across storms, seasons and years. Data quality assurance measures will include regular cleaning to minimize biofouling, blank and standard checks, and grab sample analysis to validate sensor measurements. We will compare measurements from the Lamprey River main stem with identical measurements in headwater catchments of varying land use and in the Great Bay itself. Our outreach objective is to increase knowledge about nutrient influences to help communities consider and prioritize land use planning, policies and practices that are most likely to be effective in reducing N loading.
Objective I – To generate transcriptome data from clam hemocytes sampled during the transition from normal to leukemic hemocytes while exposed to high temperature, low pH or both during an increase in viral load (i.e., viremia). This part of the project will assist us in determining which genes are up- or down-regulated as the disease develops. One of these that we know is up-regulated is the mitochondrial heat shock protein the expression of which is subject to environmental stressors like temperature and pH.
Objective II – Development of outreach programs to transfer critical habitat information gained from this study regarding the effects of temperature and pH stressors during generation of clam leukemia, as well as to transfer more broadly information about the linkage between environmental stressors and shellfish productivity to resource managers, conservation biologists and coastal communities.
Building upon previous research regarding flood risk in the Lamprey River Watershed and associated legal analysis (http://100yearfloods.org), we are working on a three-part follow-up project to enhance community resilience to future freshwater flooding by: (1) estimating potential flood damage and cost avoidance resulting from different land use management strategies in the Lamprey River Watershed; (2) training municipal officials and regional planners on the use of our "new" 100-year floodplain maps, the key findings from the Vermont Law School legal analysis, and the new economic flood damage and cost avoidance analyses; and (3) developing and implementing an innovative communication effort to broadly disseminate the results to key audiences within the watershed.
The N.H. seacoast region's physical infrastructure is at increasing and critical risk from climate-driven stressors due to both ambient and periodic extremes in precipitation and temperature, as well as from sea level rise resulting in increased inundation and rising groundwater tables. Anticipated changes could change the frequency, duration and severity of road failures as well as the time and cost of reconstructing the pavement systems. This research will develop the data and tools needed to assess climate impacts on roadways and create and engage a new N.H. Seacoast Transportation Climate Working Group to make the results readily useable by regional stakeholders. This will be accomplished by developing and engaging a N.H. seacoast transportation climate working group, conducting pavement assessments, and evaluating different adaptation strategies. The N.H. seacoast region's municipal and state road agents are our primary end users and regional planners are our secondary end user community. The PIs will work with established organizations, the UNH Technology Transfer Center and the Coastal Adaptation Workgroup to reach the targeted end users. Benefits to the end users include an expanded network of collaborators and climate change transportation infrastructure impacts and adaptation knowledge appropriate for municipal planning and decision making.