Bay scallop Argopecten irradians irradians populations and fisheries in the Peconic Bays of eastern Long Island, New York, USA, were decimated by brown tide algal blooms between 1985 and 1995. Despite the absence of brown tide since 1995, populations did not recover on their own over the next 11 yr. We hypothesized that this was due to recruitment limitation and initiated an intensive restoration program to jump-start populations by planting several million hatchery-reared scallops at high densities to ensure high fertilization success and boost larval supply. We observed 11-to 32-fold increases in larval recruitment in different embayments by 2010, compared to the period 2005 to 2006 (before intensive restoration); the most dramatic increase (3239%) occurred in Orient Harbor, the focus of restoration efforts. Recruitment was highly correlated with our index of total fertilized egg production in Orient Harbor and Hallock Bay, but not in 2 other embayments-where larval export or population overestimation probably compromised the correlation. Resurgent recruitment following restoration was not correlated to coincidental changes in adult fecundity, water temperature, salinity, rainfall, chlorophyll a, total particulate nitrogen, or local winds; decreased planktonic predation and allochthonous larval infusion were deemed unlikely drivers. We conclude that Peconic bay scallops were recruitment-limited following the 1995 brown tide and that resurgent recruitment was driven, initially, by our intensive restoration efforts and later by the rebuilding natural populations. Sustained restoration, conducted with high scallop numbers/densities, may help boost natural populations above threshold levels at which they become self-sustaining.
Intensive efforts to restore bay scallop Argopecten irradians irradians populations and fisheries in the Peconic Bays of eastern Long Island, New York, USA, were begun in 2006, following a 12 yr period during which commercial fishery landings averaged 1 to 2% of historical levels seen prior to 1985 to 1995 brown tide algal blooms. Compared to 2005 to 2006, natural population densities of 0+ yr scallops in fall increased 16 × by 2007 in Orient Harbor (OH), the focus of our restoration efforts; by 2009, densities in OH and other, unplanted, embayments had increased by 110 × and up to 331 ×, respectively. Spatial and temporal patterns paralleled those documented for larval recruitment; highly significant correlations between commercial harvest levels and both baywide larval settlement and juvenile benthic densities were revealed. Official fishery landings were 13 × those of pre-restoration levels by 2010 and have remained relatively stable through 2013. Following commencement of restoration, dockside revenues and economic benefit to the regional economy have increased by ~US$2 million and $20 million, respectively; our calculations suggest that these figures are 40% of actual numbers. Population resurgence is not correlated to temporal changes in predator populations or submerged aquatic vegetation cover. We conclude that rebuilding of Peconic bay scallop populations and fisheries has been driven by dramatic increases in bay scallop larval supply emanating from our intensive restoration efforts. By definition, we cannot say that Peconic bay scallops have attained an alternate stable state, but it is clear that dramatic increases in populations, fishery landings, and economic value are possible in just a few years.
Globally, anthropogenic activities have degraded many estuarine habitat types, including seagrass meadows. The objective of this study was to identify the degree to which light and nutrients limit the productivity of eelgrass Zostera marina in Long Island estuaries (NY, USA) while concurrently assessing the ability of hard clams Mercenaria mercenaria to influence Z. marina growth and production. Field surveys were conducted to quantify the extent of eelgrass beds, along with environmental factors potentially constraining eelgrass growth. Experimental studies were conducted to determine the extent to which eelgrass is light-or nutrient-limited within the system, and to determine the capacity of hard clams to enhance eelgrass growth in situ. Eelgrass was found in only 14% of the sites sampled, but hard clams were found in 67% of sites with eelgrass. There was a strong longitudinal light gradient in Shinnecock Bay, with an extinction coefficient of 0.88 at the ocean inlet and 2.05 in the most remote regions. Pelagic light levels were inversely correlated with water column chlorophyll levels (p = 0.0027) and eelgrass productivity was strongly correlated with light levels (p < 0.0004), with both being maximal near the ocean inlet. In estuarine regions with high light levels but significantly lower sediment nitrogen (N) content (near ocean inlet), hard clam or sediment nutrient additions yielded significantly higher eelgrass productivity and leaf N content (p < 0.001) compared to control plots. Combined with prior research, this study demonstrates that restoration of bivalves may benefit the expansion of eelgrass beds in shallow estuaries by relieving light and/or nutrient limitation.
What are the requirements on computer-an d telecommunications-based tools to aid groups i n producing intellectual products? In this article we examine research collaborations as a particularl y informative example of group work and propose a framework for describing research collaboratio n that should provide guidance to those developin g technology to support collaborative work. Th e framework is based on 50 semistructured interview s with researchers in psychology, managemen t science, and computer science . It focuses on th e problems in forming and maintaining persona l relationships and completing tasks that researcher s must solve to have a successful collaboration . Thes e problems occur when collaborators are initiatin g projects, executing them, and documenting results .
Edge effects are a dominant subject in landscape ecology literature, yet they are highly variable and poorly understood. Often, the literature suggests simple models for edge effects-positive (enhancement at the edge), negative (enhancement at the interior), or no effect (neutral)--on a variety of metrics, including abundance, diversity, and mortality. In the marine realm, much of this work has focused on fragmented seagrass habitats due to their importance for a variety of commercially important species. In this study, the settlement, recruitment, and survival of bay scallops was investigated across a variety of seagrass patch treatments. By simultaneously collecting settlers (those viable larvae available to settle and metamorphose) and recruits (those settlers that survive some period of time, in this case, 6 weeks) on the same collectors, we were able to demonstrate a "balance" between positive and negative edge effects, resulting in a net neutral effect. Scallop settlement was significantly enhanced along seagrass edges, regardless of patch type while survival was elevated within patch interiors. However, recruitment (the net result of settlement and post-settlement loss) did not vary significantly from edge to center, representing a neutral effect. Further, results suggest that post-settlement loss, most likely due to predation, appears to be the dominant mechanism structuring scallop abundance, not patterns in settlement. These data illustrate the complexity of edge effects, and suggest that the metric used to investigate the effect (be it abundance, survival, or other metrics) can often influence the magnitude and direction of the perceived effect. Traditionally, high predation along a habitat edge would have indicated an "ecological trap" for the species in question; however, this study demonstrates that, at the population level, an ecological trap may not exist.
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