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East Machias, ME, United States

The University of Maine at Machias is one of seven campuses in the University of Maine System. Located in Machias, Maine, United States, the seat of Washington County, the university was founded in 1909 as a normal school for educating teachers, and offers studies in recreation, education, Psychology & Community Studies and physical science, including a recognized marine biology program. Enrollment is approximately 1,200 students. Wikipedia.

Beal B.F.,University of Maine at Machias | Protopopescu G.C.,Downeast Institute for Applied Marine Research and Education
Journal of Shellfish Research

Historically, stock enhancement programs for American lobster, Homarus americanus, have a common theme: production and release of large numbers of stage IV or stage V individuals. However, these animals are difficult to mark, highly mobile when released on the bottom, and susceptible to a wide array of predators, and their claws have yet to develop bilateral asymmetry. Many of these attributes make it difficult to test the efficacy of hatch-and-release efforts. It is possible to hold postlarval lobsters individually in the laboratory or hatchery and provide food regularly for several months to release older, larger individuals (as with enhancement efforts in Europe with Homarus gammarus). However, the costs to do so compared with the value of commercial-size animals makes this practice cost prohibitive. Attempts to reduce costs of rearing early postlarvae to larger sizes in ocean-based nursery cages in eastern Maine for periods of longer than 1 y have resulted in variable survival (in general, <50%) and slow growth (doubling in carapace length (CL) from 4.28.9 mm). A series of field trials (2004 to 2010) examined methods to improve survival rates and enhance growth with the goal of producing animals large enough to apply a physical tag that can be seen easily by fishers and scientists interested in testing directly the efficacy of enhancement efforts. The effect of flow rates into and out of various types of containers (350 mL and 440 mL) holding individual, cultured stage IV lobsters was examined experimentally during a 309-day period from August 2004 to July 2005 in off-bottom, ocean-based nursery cages deployed in shallow (12 m) water near Great Wass Island, Beals, ME. Mean survival rate varied directly with flow as animals in containers with the greatest exchange of seawater demonstrated survival rates of ca. 90% compared with ca. 30% in containers allowing lower flow rates. Sediment deposition in the low-flow rate containers tended to be high, and was associated with significantly lower mean lobster survival. In a separate field trial in shallow water from August 2009 to October 2010 (419 days), lobster growth in submerged wooden trays was assessed using 5 different container sizes that ranged from 0.020.26 m 2 (ca. 1.521 L). Growth was best described by a sigmoidal function, with a strong linear component over container sizes between 0.02 m 2 and 0.13 m 2 (ca. 1.510 L), and no significant difference observed in mean CL of lobsters in the largest 2 container sizes. Final mean CL and mass (23.9 ± 1.4 mm and 10.7 ± 2.1 g, respectively, ±95% CI) of animals in the 2 largest containers was 57.4% and 349% greater, respectively, than animals in the smallest containers. Rearing cultured individuals of H. americanus to large sizes in ocean-based nursery cages may provide managers of stock enhancement programs with a more viable assessment tool than those used traditionally. Source

The commercial fishery for American lobster Homarus americanus Milne Edwards in Maine has experienced the highest landings during the past 2 decades than at any time since the 1950s. However, there is no scientific consensus on why landings have increased nearly 250% from 1990 to 2010, and no one can predict how long landings can be expected to remain at current levels. This uncertainty has sparked a renewed interest in lobster stock enhancement using cultured individuals. Historically, lobster stock enhancement in North America has focused primarily on releasing early benthic phase (stage IV) animals. It is not cost-effective to feed and maintain animals in the laboratory or hatchery until they are larger (ca. stage XXI), as is typical of enhancement efforts with cultured individuals of Homarus gammarus (L.) in Europe, even though survival to commercial size presumably would be greater. One difficulty with releasing early benthic phase animals is that they have the capacity to swim away from the release site, making tests to determine the efficacy of such programs logistically difficult and expensive. A low-cost, low-maintenance, ocean-based nursery grow-out system for stage IV H. americanus was tested in waters off eastern Maine using technology first developed and implemented successfully for cultured individuals of H. gammarus in Ireland. A single individual was added to a plastic soda bottle (ca. 350 mL) or Petri dish (440 mL) containing a series of small holes to allow continuous flow of seawater into and out of the units. Bottles (n = 630) and dishes (n = 420) were added to rigid nursery cages constructed of traditional vinyl-coated lobster trap wire and deployed in July 2002 ca. 2 m off the bottom in depths of 10 m, 15 m, and 25 m in and around Chandler Bay near Jonesport. After nearly 70 days, survival in the bottles varied from 20% at the deepwater site to 90% at the shallow-water site; however, after an additional 244288 days, most bottles had filled with muddy sediments, and mortality rate was nearly 100%. Conversely, survival rates after 448 days in the dishes varied, on average, from 21.547.2% per cage originally deployed at the deepest and shallowest site, respectively. Growth rates in the dishes generally doubled during the 14-mo field trial from a carapace length of 4.2 mm to that of 8.9 mm. Results suggest that ocean nurseries can be used to rear cultured lobsters to larger sizes prior to release for stock enhancement purposes; however, these animals are too small to apply visible tags (i.e., streamer or T-bar tags) that fishers could discern easily. Source

Jillette N.,University of Maine at Machias | Jillette N.,Auburn University | Cammack L.,Auburn University | Cammack L.,Mt Desert Island Biological Laboratory | And 4 more authors.
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology

The euryhaline green crab, Carcinus maenas, undergoes an annual cycle of salinity exposure, having to adapt to low salinity during its annual spring migration into estuaries, and then having to re-adapt to high salinity when it moves off-shore at the end of summer. Most studies have focused on low salinity acclimation, the activation of osmoregulatory mechanisms, and the induction of transport protein and transport-related enzyme activity and gene expression. In this study we followed the changes in hemolymph osmolality, carbonic anhydrase activity, and mRNA expression of three proteins through a complete cycle of low (15. ppt) and high (32. ppt) salinity acclimation. One week of low salinity acclimation resulted in hemolymph osmoregulation and a four-fold induction of branchial carbonic anhydrase activity. Relative mRNA expression increased for two CA isoforms (CAc 100-fold, and CAg 7-fold) and the α-subunit of the Na/K-ATPase (8-fold). Upon re-exposure to high salinity, hemolymph osmolality increased to 32. ppt acclimated levels by 6. h, and mRNA levels returned to high salinity, baseline levels within 1. week. However, CA activity remained unchanged in response to high salinity exposure for the first week and then gradually declined to baseline levels over 4. weeks. The relative timing of these changes suggests that while whole-organism physiological adaptations and regulation at the gene level can be very rapid, changes at the level of protein expression and turnover are much slower. It is possible that the high metabolic cost of protein synthesis and/or processing could be the underlying reason for long biological life spans of physiologically important proteins. © 2010. Source

News Article
Site: http://phys.org/biology-news/

Blue mussels, Mytilus edulis, live on northern Atlantic shores in the area between high and low tides. "Mussels are one of the most significant filter-feeders in the marine environment," said Brian Beal, a marine ecologist at the University of Maine at Machias. "They are responsible not only for efficiently producing high-quality protein but for cleaning the waters around them through their feeding activities." Because many creatures--especially humans--enjoy eating blue mussels, farmers grow mussels using aquaculture, or aquatic farming. Beal, along with a team of NSF-funded researchers at the University of Maine at Machias and the Downeast Institute, is investigating the growing conditions and practices that will reliably yield healthy and plentiful blue mussels. The researchers also are investigating exactly when to transition the young mussels into ocean pens, and where in the pens they grow best. Find out more in this discovery. Credit: Brian Beal, University of Maine at Machias, Division of Environmental and Biological Sciences These tiny creatures are Arctic surfclams. They're getting packed up for a trip to the shore. With some help, they're about to take up residence in an intertidal mudflat on the Maine coast, or 'Downeast' as they say around here, referring to ships sailing centuries ago from Boston east to Maine and downwind. The area's rich maritime history is not lost on Brian Beal, a marine ecologist with the University of Maine at Machias who has lived here all of his life and grew up working on the water. With support from the National Science Foundation (NSF), Beal and a team based at the university's Marine Science Field Station at the Downeast Institute are putting their aquaculture innovation skills to work. The team's goals are to diversify the U.S. market for shellfish and increase the number of jobs in that market. The researchers are focused on two types of shellfish with the potential to bring more jobs and dollars to the area: blue mussels and Arctic surfclams. In the case of the latter, Arctic surfclams are not only a valuable species, but, Beal says, no one has ever tackled culturing them before. Arctic surfclams are a deepwater species that range from Rhode Island north to Newfoundland. Low densities have so far prevented the species from becoming a highly valued fishery in the U.S., but in Canada, there's a $50 million fishery off the southeast coast of Halifax, Nova Scotia, and off the Grand Banks, south of Newfoundland. The other species, blue mussels, aren't new to Maine. They've been a part of the seafood industry here for years. Beal would like to expand the market for blue mussels by making cultivation more of a turnkey operation by providing mussel growers with a choice between collecting wild seed (that depends each year on the vagaries of nature) and a more consistent hatchery-reared seedling. This is a Partnerships for Innovation: Building Innovation Capacity (PFI: BIC) project, which is focused on examining opportunities to create new marine aquaculture jobs in coastal Maine through shellfish research. The broader impacts of this research are related to increasing U.S. competitiveness in the seafood industry. "This NSF PFI project embodies a quintessential combination of science, engineering, technology, education, outreach and the pursuit of innovation," says Sara Nerlove, program director for the PFI: BIC program. "And because Brian Beal was born and raised in the area, we have a special research situation, one in which he's been able to capitalize on his thorough knowledge of the people and the local economy." Explore further: Key discovery made in war on sea lice infestations

Aguirre J.D.,Victoria University of Wellington | Aguirre J.D.,University of Queensland | McNaught D.C.,Victoria University of Wellington | McNaught D.C.,University of Maine at Machias
Marine Ecology Progress Series

Predation strongly influences the abundance and distribution of prey populations due to its disproportionately large effects on survival during the early life-history stages. However, the intensity of predation can vary dramatically among habitats. The habitat can directly affect the interaction between predator and prey; but also, by determining the distributions of predators and prey, the habitat can mediate the likelihood of a predatory encounter. Here, we used laboratory experiments to identify the likely predators of juvenile abalone Haliotis iris on temperate reefs in central New Zealand. Predator performance in the laboratory was assessed in conditions without prey refuge, in simulated juvenile habitat as well as in the presence of alternate prey. We then used surveys to compare the abundance of predators and juvenile abalone to explore if negative associations between predator and prey in the laboratory manifest in the field. Last, we manipulated algal habitat complexity at 2 depths and quantified the effect of predator exclusion on juvenile abalone survival in the field. We found that starfish were the likely predators of juvenile H. iris in our study system. Furthermore, predation of juvenile abalone by starfish was lowest in habitats with the greatest structural complexity, and there is evidence that predation by starfish in cobble habitats was size-dependent. Overall, we found that habitat variability mediates predation on juvenile abalone by determining the likelihood of an encounter between predator and prey. © Inter-Research 2013. Source

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