Research

Selected Research Articles 1998–2000
Click here for selected research articles 2001–Present

Below are abstracts of Rhode Island Sea Grant–funded research articles. To order a copy of the article, contact Rhode Island Sea Grant Communications at (401) 874-6842.

The National Sea Grant Library is the official Sea Grant archive. Library staff lend documents all over the world and maintain a searchable bibliographic database where you may obtain citations and abstracts of Sea Grant publications and, in many cases, a full text copy of the document.

Eelgrass | Fisheries Economics | Fishing Gear | Fishing/Risk | Greenwich Bay | Lobster | Marine Archaeology | Marine Sanctuaries | Seafood Safety | Summer Flounder

Eelgrass

• Bintz, Joanne C. and Scott W. Nixon, 2000. Responses of eelgrass Zostera marina seedlings to reduced light. Marine Ecology Progress Series 223: 133-141, 2000.
RIU-R-01-006 (P1632); 9pp.

Transplanting eelgrass beds is one method of restoration researchers have attempted, but eelgrass seeds and seedlings also hold potential for eelgrass restoration. This article describes how seedlings respond to reduced light in experimental conditions-while most survive, their growth and long-term survival potential is compromised.

Fisheries Economics

• Holland, Daniel S., 2000. A bioeconomic model of marine sanctuaries on Georges Bank. Canadian Journal of Fisheries and Aquatic Sciences, 57:1307-1319, 2000.
RIU-R-00-002 (P1598); 13pp.

Increasing interest in the use of marine sanctuaries as fisheries management tools to protect habitat and reduce fishery depletion calls for research into the efficacy of varying strategies. A lack of empirical evidence has motivated the development of computer models to explore the effects of closed areas. A bioeconomic model in this study is used to explore how permanent marine sanctuaries on Georges Bank might affect catches, revenues, and spawning stock of principal groundfish species in New England. The simulations explore how the spatial orientation of sanctuaries relative to major ports and seasonal movement of fish stocks impact their effectiveness and the distribution of benefits across groups of fishers from different ports. Results demonstrate that the impacts of sanctuaries can vary greatly across species. While results reflect the characteristics of the New England groundfish fishery, the modeling methodology and some general conclusions are applicable to other fisheries.

• Holland, Daniel S. and Jon G. Sutinen, 1999. An empirical model of fleet dynamics in New England trawl fisheries. Canadian Journal of Fisheries and Aquatic Science, 56:253-264, 1999.
RIU-R-99-014 (P1582); 12pp.

Regulations and changes in market and environmental conditions that alter the profitability of one fishery or area will result in a redistribution of fishing effort among alternative fisheries or areas. The authors of this paper present an empirical model of individual vessel fishery and location choice based on trip data for a group of over 400 large trawlers fishing in New England. The model uses lagged average revenue rates for different alternatives and the individual vessel's past behavior to predict choice of species group and fishing location on a trip-by-trip basis. This model is used to predict aggregate effort levels in different fisheries and areas over time.

• Kuperan, K. and Jon G. Sutinen, 1998. Blue water crime: deterrence, legitimacy, and compliance in fisheries.  Law & Society Review, 32(2): 309-338, 1998.
RIU-R-98-013 (P1581); 20pp.

The authors of this report used Probit and Tobit econometric estimators to examine the compliance behavior of 318 Malaysian fishermen who face a regulation banning them from fishing in a zone along the coast. The theoretical models of compliance behavior tested include the basic deterrence model, which focuses on the certainty and severity of sanctions as key determinants of compliance, and models which integrate economic theory with theories from social psychology to account for legitimacy, deterrence, and other motivations expected to influence individuals' decisions whether to comply. The results of the empirical analysis provide additional evidence on the relationship of deterrence and legitimacy to compliance. The findings are also used to draw implications for compliance policy for regulated fisheries.

• Sutinen, Jon G. and K. Kuperan, 1999. A socio-economic theory of regulatory compliance. International Journal of Social Economics, 26(1/2/3): 174-193, 1999.
RIU-R-99-015 (P1583); 20pp.

An enriched theoretical model of regulatory compliance is developed in this paper. The model integrates economic theory with theories from psychology and sociology to account for both tangible and intangible motivations influencing individuals' decisions whether to comply with a given set of regulations. Taken account of are moral obligation and social influence along with the conventional costs and revenues associated with illegal behavior. While cast in a natural resource management context, the theory developed here is applicable to a variety of institutional conditions. The resulting framework can enhance the design and implementation of compliance and regulatory programs.

Fishing Gear

• Collie, J.S. et al. 2000. Photographic evaluation of the impacts of bottom fishing on benthic epifauna. ICES Journal of Marine Science 57:987-1001.

The gravel sediment habitat on the norther edge of Georges Bank is an important nursery area for juvenile fish and the site of a productive scallop fishery. For this work, researchers examined photographs and videos of transects at sites of varying degrees of disturbance from otter trawling and scallop dredging. Results indicate that certain epifauna that provide habitat for several species were conspicuously less abundant at disturbed sitse.

• Collie, J.S. et al. 2000. A quantitative analysis of fishing impacts on shelf-sea benthos. Journal of Animal Ecology 69:785-798.
RIU-R-00-010 (P1662); 14pp.; $3.00.

This analysis of 39 published fishing impact studies shows that intertidal dredging and scallop dredging have the greatest initial effects on benthic biota, while trawling has less effect. Fauna in stable gravel, mud, and biogenic habitats are more adversely affected than those in less consolidated sediments. Areas that are fished in excess of three times per year are likely to remain in a permanently altered state.

• DeAlteris, Joseph et al., 1999. The significance of seabed disturbance by mobile fishing gear relative to natural processes: a case study in Narragansett Bay, Rhode Island. American Fisheries Society Symposium, 22:224-237, 1999.
RIU-R-99-001 (P1527); 15pp.

Seabed disturbance by mobile bottom-fishing gear has emerged as a major concern related to the conservation of essential fish habitat. However, the seabed is also disturbed by natural physical and biological processes. The biological communities that utilize a particular habitat have adapted to that environment through natural selection and, therefore, the impact of mobile fishing gear on the habitat structure and biological community must be scaled against the magnitude and frequency of seabed disturbance due to natural causes. Fishers operating in the mouth of Narragansett Bay, Rhode Island use trawls to harvest lobsters, squid, and finfish and dredges to harvest mussels. Side-scan sonar data indicate that evidence of bottom scarring by the fishing gear is restricted to deeper waters with a seabed composition of soft cohesive sediments. A quantitative model has been developed to compare the magnitude and frequency of natural seabed disturbance to mobile fishing gear disturbance. The application of this model on a larger scale to continental shelf waters and seabed sediment environments will allow for the identification of problematic areas relative to the degradation of essential fish habitat by mobile fishing gear.

Fishing/Risk

• Pollnac, Richard B. et al., 1998. Thresholds of danger: perceived risk in a New England fishery.  Human Organization, 57(1): 53-59, 1998.
RIU-R-98-001 (P1487)

Fishing the North Atlantic is extremely hazardous, yet fishers have adopted to the ever-present perils of the sea.  Aspects of the occupational subculture of fishing that adapts fishers to these dangers, and the implication of these adaptations with respect to fisher safety training, are the focuses of the article. Previous research has demonstrated fishers' denial of the risks involved, as well as variability in both perceptions of, and coping mechanisms used to deal with, specific dangers among fishers.

Greenwich Bay

• August, P. et al., 2000. Greenwich Bay and its watershed: Spatial data for planning and environmental management. Paper No. 2 in M. Schwartz (ed.) Restoring Water Quality in Greenwich Bay: A Whitepaper Series. Rhode Island Sea Grant, Narragansett, R.I. 8pp.

Since land management decisions require current and accurate data about the environment at the level of land parcels, a more detailed resource of spatial data was needed by the city of Warwick than the geographic information systems database available from the Rhode Island GIS program. This paper describes the development of large-scale digital orthophotos and accompanying database, as well as the implementation of a citywide GIs and the dissemination and evaluation of the information.

• Granger, Steve et al., 2000. An assessment of eutrophication in Greenwich Bay. Paper No. 1 in M. Schwartz (ed.) Restoring Water Quality in Greenwich Bay: A Whitepaper Series. Rhode Island Sea Grant, Narragansett, RI 20pp.

To assess eutrophication in Greenwich Bay, researchers obtained actual measurements of dissolved oxygen, temperature, and salinity at various depths throughout the bay during a complete annual cycle. They also measured the amount of plant material growing in the bay and compared the various sources of nutrients that were stimulating and supporting plan growth. This whitepaper describes their findings and includes discussion of the history of water quality in the bay and potential impacts of expanded sewering of Warwick.

• Gomez, Anthony L. and Daniel W. Urish, 1998. Determination of the quantity, quality, and location of coastal groundwater discharge to a marine embayment:  Greenwich Bay, Rhode Island.
RIU-T-98-005 (P1525); 100pp.

This 100-page study, including tables and charts, was conducted to determine the effect sewering would have in reducing nitrogen loading to Greenwich Bay, RI. Nitrogen is a major component of sewage effluent and a major factor in causing eutrophication. The study includes delineation of the watershed and 23 sub-basins, development of a water budget and nitrogen budget predictive model using GIs software, installation of monitoring wells, and measurement of groundwater seepage. It is predicted that complete sewering of the watershed would reduce the total nitrogen to 65.8 kg/day, a reduction of 82%.

Lobster

• Castro, Kathleen M. and Thomas E. Angell, 2000. Prevalence and progression of shell disease in American lobster, "Homarus americanus," from Rhode Island waters and the offshore canyons.  Journal of Shellfish Research, 19(2): 691-700, 2000.
RIU-R-00-006 (P1610);10pp.

From 1995 to 1999, shell disease in lobsters, "Homarus americanus," was monitored in research trawl and trap surveys conducted in Rhode Island waters and the offshore areas of Block and Hudson Canyons. Scientists documented a significant increase in frequency and severity of the disease over time, reaching 20% infected by 1999 with more than 50% of ovigerous females affected. Shell disease was noted in the offshore lobster population beginning 1998. A tag-recapture study conducted in Narragansett Bay followed the change in severity over a 3-year period for 86 individuals. Observed disease pathways point to potential effects on reproductive behavior and mortality. The proportion infected with disease appeared to diminish over the molting period, but subsequently increased during the months of September and October.

• Clancy, Michael and Stanley J. Cobb, 1999. Habitat-based assessment of lobster abundance: a case study of an oil spill. American Fisheries Society Symposium, 22:285-298, 1999.
RIU-R-99-002 (P1528); 14pp.

The pollution event the authors studied was the result of the grounding of a tug and barge loaded with No. 2 fuel oil on the southern Rhode Island coast in a fierce storm on 19 January 1996. The barge spilled over 3 million liters of oil, contaminating an approximately 13-km stretch of shoreline. They report a habitat-based effort to assess loss to the lobster population, and had two objectives.  First, was there a statistically significant effect of the oil? Second, how many lobsters were in the affected area before and after the accident? Conceptually simple approaches provided challenges in sampling and statistical analyses, and in deriving absolute density from sample density. Loss estimates ranged from 6-15 million lobsters of all sizes, the mode of the airlift samples being 15mm carapace length.

• James-Pirri, Mary-Jane, 1998. Influence of settlement time and size on postsettlement growth in the American lobster "Homarus americanus". Canadian Journal of Fisheries and Aquatic Sciences, 55:2436-2446, 1998.
RIU-R-98-007 (P1526); 11pp.

In this paper, the authors investigated the size and timing of settlement of postlarval (fourth instar) American lobster and the size attained by the end of the first growing season. For all years (1988-1995), postlarvae present early in the season were 30-50% larger (carapace length) and two or three instars further developed than late settlers by the end of the growing season. Although initial carapace length at settlement was important, the timing of settlement was more influential on the size attained by the end of the first growing season.

• James-Pirri, Mary-Jane and Stanley J. Cobb, 2000. Influence of size and delayed settlement on the recapture rate of newly settled American lobsters "Homarus americanus." Marine Ecology Progress Series, 208:197-203, December 8, 2000.
RIU-R-00-007 (P1613)

Postlarval American lobsters "Homarus americanus" exhibit variation in size at settlement and timing of settlement but it is not known if this variability influences future survival. In this study micro-wire tags were used to identify individual postlarval and fifth instar lobsters that were released into the field and then recaptured 1 wk later. The influence of size at settlement and timing of settlement on subsequent recapture rate (a proxy for settlement success) were determined. Larger sized postlarvae and fifth instar lobsters were recaptured significantly more frequently than their smaller counterparts. There was no difference in recapture rate for postlarvae that delayed settlement, as compared to those that settled at the normal time. The authors discuss several possible explanations.

• James-Pirri, Mary-Jane and Stanley J. Cobb, 1999. Behavioral interactions of postlarval and fifth instar lobsters ("Homarus americanus") in a simulated cobble environment. Marine and Freshwater Behaviour and Physiology, 32:207-222, 1999.
RIU-R-99-006 (P1550); 16pp.

In the American lobster ("Homarus americanus"), the fourth or postlarval instar makes the behavioral and ecological transition from the planktonic to the benthic environment. Shortly after settlement to the benthos, the postlarval instar molts to the fifth instar, and becomes a truly benthic organism. In this study, researchers investigated behavioral interactions among postlarval and fifth instar lobsters in a simulated cobble environment. Postlarvae were observed spending a large proportion of time walking on the substrate and excavating shelters, whereas fifth instar lobsters spent the majority of time excavating and sitting in shelters. Dominance hierarchies and burrow invasion and eviction were observed in both instars.

• James-Pirri, Mary-Jane and Stanley J. Cobb, 1999. Influence of coded micro-wire tags on postlarval lobster ("Homarus americanus") behavior. Marine and Freshwater Behaviour and Physiology, 32:255-259, 1999.
RIU-R-99-007 (P1551)

This laboratory study investigated the influence of coded micro-wire tags on the behavior of postlarval American lobsters, "Homarus americanus", in a simulated cobble environment. Newly settled postlarvae were divided into two treatment groups, tagged and untagged. Seven behavioral categories were identified and the proportion of time spent in each for each treatment was evaluated. The researchers conclude that the presence of micro-wire tags does not influence behavior of newly settled lobsters.

Marine Archaeology

• Abbass, D. K. and Joseph W. Zarzynski, 1998. The Rhode Island ship "Gem": slaver or propaganda. Underwater Archaeology, Babits, Lawrence E., et al., (eds.), pp. 74-78, 1998.
RIU-R-98-005 (P1515)

This report details the history of a bark ship, known as "Gem", run off the coast of Rhode Island in 1856. The Rhode Island Marine Archaeology Project has tried to prove that the "Gem" was a slave ship; no conclusive proof has been established yet.

Marine Sanctuaries

• Holland, Daniel S., 2000. A bioeconomic model of marine sanctuaries on Georges Bank. Canadian Journal of Fisheries and Aquatic Sciences, 57:1307-1319, 2000.
RIU-R-00-002 (P1598); 13pp.

Increasing interest in the use of marine sanctuaries as fisheries management tools to protect habitat and reduce fishery depletion calls for research into the efficacy of varying strategies. A lack of empirical evidence has motivated the development of computer models to explore the effects of closed areas. A bioeconomic model in this study is used to explore how permanent marine sanctuaries on Georges Bank might affect catches, revenues, and spawning stock of principal groundfish species in New England. The simulations explore how the spatial orientation of sanctuaries relative to major ports and seasonal movement of fish stocks impact their effectiveness and the distribution of benefits across groups of fishers from different ports. Results demonstrate that the impacts of sanctuaries can vary greatly across species. While results reflect the characteristics of the New England groundfish fishery, the modeling methodology and some general conclusions are applicable to other fisheries.

Seafood Safety

• Gudmundsson, Eyjolfur and Cathy R. Wessells, 2000. Ecolabeling seafood for sustainable production: implications for fisheries management. Marine Resource Economics, 15:97-113, 2000.
RIU-R-00-008 (P1623); 17pp.

Demand for environmental quality of a fishery product and its effect on the incentive to manage fisheries sustainably is analyzed using bioeconomic modeling. The paper examines the effectiveness of an ecolabel in achieving sustainable fisheries production under open-access, limited-access, and optimally managed fisheries with price premiums for ecolabeled products that are either constant or a function of sustainability criteria. In addition, the paper investigates the effect of placing an ecolabel on the rate of recovery of an overfished stock.

• Wessells, Cathy R. et al., 1999. Assessing consumer preferences for ecolabeled seafood: the influence of species, certifier, and household attributes. American Journal of Agricultural Economics, 81(5): 1084-1089, 1999.
RIU-R-99-017 (P1600)

A major ecolabeling initiative is under way for global marine fisheries. The Marine Stewardship Council (MSC) was formed in 1996 to provide a mechanism for labeling selected seafood products worldwide. The purpose of the labeling initiative is to provide a market-based incentive to maintain sustainable fish stocks, given that command-and- control regulations are notorious for their failures. Changing the behavior of consumers to affect fisheries significantly requires an integrated campaign to increase awareness and understanding of the environmental issues and an understanding of the connection between sustainable fisheries and seafood purchase decisions. Results of this analysis suggest that preferences for ecolabeled fish will likely differ by species, geographic region, consumer group, and perhaps by certifying agency.

• Wu, Q. et al., 1998. Differentiation of algae clones on the basis of resonance Raman spectra excited by visible light. Analytical Chemistry, 70(9): 1782-1787, 1998.
RIU-R-98-009 (P1556)

Fourteen algae clones belonging to four different classes, including clones of "Pseudo-nitzschia" (Bacillariophyceae), some of which are capable of producing the toxin domoic acid, were studied by means of resonance Raman spectra excited at 457.9 and 488 nm. Similarities and differences among spectra were analyzed by the method of principal component analysis (PCA). A distinct clustering of spectral data according to algal class were shown by PCA score plots. All "Pseudo-nitzschia" clones can be separated from other classes of algae on the basis of spectra, but it is not possible to distinguish toxic "Pseudo-nitzschia" from nontoxic clones on the basis of these spectra, which reflect only differences in carotenoid composition.

Summer Flounder

• Alves, David et al., 1999. Investigations into the causes of early larval mortality in cultured summer flounder ("Paralichthys dentatus" L.).  Aquaculture, 176:155-172, 1999.
RIU-R-99-016 (P1594); 18pp.

In the Northwest Atlantic, severe restrictions on the allowed catch of summer flounder may make both commercial aquaculture and stock enhancement economically attractive. In this species, a period of high mortality occurs from hatch through first feeding. Successful first feeding, in which larvae make the transition from endogenous to exogenous nutrient supply, is critical to survival. The authors of this paper studied larval mortality in cultured summer flounder during the first 2 weeks after hatch. They discuss the influence of feeding success, parentage, addition of algae, water quality, and the microbial community on mortality during this period.

• Bengtson, D. A., 1999. Aquaculture of summer flounder ("Paralichthys  dentatus"): status of knowledge, current research and future research priorities. Aquaculture, 176:39-49, 1999.
RIU-R-99-013 (P1570); 11pp.

The author of this review has surveyed the existing literature on the aquaculture of summer flounder, and describes here ongoing research efforts, methods of current production, and research needs for the future.

• Schreiber, Alex M. and Jennifer L. Specker, 1999. Metamorphosis in the summer flounder "Paralichthys dentatus": changes in gill mitochondria-rich cells. The Journal of Experimental Biology, 202:2475-2484, 1999.
RIU-R-99-012 (P1566); 10pp.

Salinity tolerance changes during larval development and metamorphosis in the summer flounder ("Paralichthys dentatus") and other teleosts. This study characterized changes in ultrastructure, intracellular membranes and immunoreactive NaﲯATPase of mitochondria-rich cells (MRCs) in the gills of summer flounder during metamorphosis. Gill MRCs were assessed for changes in ultrastructure using transmission electron microscopy and changes in intracellular membranes by reactivity to osmium. Findings suggest that gill MRCs develop during the metamorphosis of summer flounder as the gill takes on an increasingly important osmoregulatory role.

• Soffientino, Bruno et al., 1999. Infectious necrotizing enteritis and mortality caused by "Vibrio carchariae" in summer flounder "Paralichthys dentatus" during intensive culture.  Diseases of Aquatic Organisms, 38:201-210, 1999.
RIU-R-99-008 (P1554); 10pp.

In this paper, the authors report on an epizootic that caused mortality among cultured summer flounder "Paralichthys dentatus" in summer of 1998 at a land-based facility on Narragansett Bay, Rhode Island. The disease, flounder infectious necrotizing enteritis, was characterized by reddening around the anal area, distended abdomens filled with opaque serosanguineous fluid, enteritis and necrosis of the posterior intestine. A bacterium was isolated from ascites fluid and kidney of moribund flounder and identified as the causative agent in challenge experiments. The pathogen was identified as "Vibrio carchariae" by morphological and biochemical characteristics and sequence of the 16S rRNA.