John T. Tanacredi

Biology and conservation of horseshoe crabs

Biology.- Limits on the Global Distribution of Horseshoe Crabs (Limulacea): Lessons Learned from Two Lifetimes of Observations: Asia and America.- Horseshoe Crabs - An Ancient Ancestry Revealed.- The Ecological Importance of Horseshoe Crabs in Estuarine and Coastal Communities: A Review and Speculative Summary.- Relationships Between Sandpipers and Horseshoe Crab in Delaware Bay: A Synthesis.- Horseshoe Crabs, Their Eco-biological Status Along the Northeast Coast of India and the Necessity for Ecological Conservation.- American Horseshoe Crabs, Limulus polyphemus, in Mexico: Open Possibilities.- Basic Habitat Requirements of the Extant Species of Horseshoe Crabs (Limulacea).- The Relationship Between Small- and Large-Scale Movements of Horseshoe Crabs in the Great Bay Estuary and Limulus Behavior in the Laboratory.- Ecology of Horseshoe Crabs in Microtidal Lagoons.- Phylogeography, Demographic History, and Reserves Network of Horseshoe Crab, Tachypleus tridentatus, in the South and East China Seaboards.- Genetic Structure of Japanese Populations of Tachypleus tridentatus by mtDNA AT-Rich Region Sequence Analysis.- Reproductive Competition and Sexual Selection in Horseshoe Crabs.- Vision in Horseshoe Crabs.- Sperm Attachment on the Egg of Malaysian King Crab, Carcinoscorpius rotundicauda.- Distribution and Development of Limulus Egg Clusters on Intertidal Beaches in Delaware Bay.- Comparisons in Prosomal Width and Body Weight Among Early Instar Stages of Malaysian Horseshoe Crabs, Carcinoscorpius rotundicauda and Tachypleus gigas in the Laboratory.- Emergence Behavior of Juvenile Tachypleus tridentatus Under Simulated Tidal Conditions in the Laboratory and at Two Different Sediment Temperatures.- Distribution of Juvenile Horseshoe Crabs in Subtidal Habitats of Delaware Bay Using a Suction-Dredge Sampling Device.- Conservation.- History of Horseshoe Crab Harvest on Delaware Bay.- Biomedical Applications of Limulus Amebocyte Lysate.- The Effect of Hemolymph Extraction Volume and Handling Stress on Horseshoe Crab Mortality.- Horseshoe Crabs in Hong Kong: Current Population Status and Human Exploitation.- Comparative Status and Assessment of Limulus polyphemus with Emphasis on the New England and Delaware Bay Populations.- An Integrative Approach to Horseshoe Crab Multiple Use and Sustainability.- Strategies to Conserve and Enhance Sandy Barrier Habitat for Horseshoe Crabs (Limulus polyphemus) on Developed Shorelines in Delaware Bay, United States.- Conservation Program for the Asian Horseshoe Crab Tachypleus tridentatus in Taiwan: Characterizing the Microhabitat of Nursery Grounds and Restoring Spawning Grounds.- The Effects of Water Quality on Horseshoe Crab Embryos and Larvae.- Heavy Metal Concentration in Horseshoe Crab (Carcinoscorpius rotundicauda and Tachypleus gigas) Eggs from Malaysian Coastline.- A Discussion of Horseshoe Crab Management in Five Countries: Taiwan, India, China, United States, and Mexico.- Clinical Evaluation, Common Diseases, and Veterinary Care of the Horseshoe Crab, Limulus polyphemus.- Aquaculture Methods and Early Growth of Juvenile Horseshoe Crabs (Limulus polyphemus).- Larval Culture of Tachypleus gigas and Its Molting Behavior Under Laboratory Conditions.- Diet Composition of Juvenile Horseshoe Crabs: Implications for Growth and Survival of Natural and Cultured Stocks.- Effect of Sediment Type on Growth and Survival of Juvenile Horseshoe Crabs (Tachypleus tridentatus).- The Conservation Network of Horseshoe Crab Tachypleus tridentatus in Taiwan.- The History of Horseshoe Crab Research and Conservation in Japan.- Public Awareness and Community-Based Conservation for the Horseshoe Crab at Saikai National Park in Nagasaki Prefecture, Japan.- Public Participation in Studies on Horseshoe Crab Populations.- Green Eggs and Sand: A Collaborative Effort of Scientists, Teachers, Resource Managers, and Stakeholders in Educating About Limulus polyphemus.- Community Building: An Integrated Approach to Horseshoe Crab Conservation.

Secondary Production of the Amphipod Ampelisca abdita Mills and Its Importance in the Diet of Juvenile Winter Flounder (Pleuronectes americanus) in Jamaica Bay, New York

The benthic amphipod Ampelisca abdita dominates mudbottom benthic communities in Jamaica Bay (New York). In this study, we investigated the trophic role of Ampelisca in relation to winter flounder (Pleuronectes americanus) populations—the most frequently trawled fish species in Jamaica Bay. Flounders collected by trawl during summer 1989 were primarily juveniles. Stomach analyses indicated that amphipod crustaceans contributed >99% of prey individuals, with A. abdita making up 88%. Density and size frequency analyses of Ampelisca at three sites indicated two overlapping cohorts: a spring cohort released in June and a summer cohort released in late summer. Most overwintering survivors come from the summer cohort. Secondary production of Ampelisca was estimated at three sites using the cohort summation of biomass method. Estimates of annual production ranged from 25 g DW to 47 g DW m−2 (mortality + residual biomass); production due to growth ranged from 20 g DW to 26 g DW. Simulations of spring cohort production using a range of plausible growth and mortality schedules suggested that P∶B may be more sensitive to variability in survivorship than growth. Ampelisca secondary production in Jamaica Bay is compared with other amphipod species and with macrobenthic production in other coastal and estuarine systems. We conclude that observed amphipod production is probably more than sufficient to support local winter flounder populations in Jamaica Bay, and we speculate that high nutrient loadings may indirectly stimulate amphipod production. *** DIRECT SUPPORT *** A01BY058 00010

Rare and endangered plants at Gateway National Recreation Area: a case for protection of urban natural areas

Abstract The diversity of native plant species in urban environments is usually overlooked when biodiversity levels are considered. Inventories of native plants reveal many to be rare species surviving the harsh conditions encountered in urban ecosystems. Knowledge of their existence and an inventory of their distribution will assist in maintaining these populations. Protection strategies for rare plant species are outlined for urban National Parks.

Changes in reproductive morphology and physiology observed in the amphipod crustacean, Melita nitida Smith, maintained in the laboratory on polluted estuarine sediments

Abstract An earlier study showed that the amphipod crustacean Melita nitida Smith maintained on sediments dosed with waste crankcase oil developed physiological and morphological abnormalities. Most notably, mature females developed abnormal setae along the edges of their brood plates. The present study was conducted to determine whether similar abnormalities might be induced in animals maintained on polluted field sediments containing petroleum by-products among other toxic substances. In the laboratory, heterosexual pairs were maintained on three sediments taken from Jamaica Bay (New York) plus one control sediment and one toxic substratum ( Ulva lactuca (L.) thalli). The results mirrored the results of the previous study. Under controlled conditions brood production was reduced on polluted sediments by as much as 57% and a greater proportion of females maintained on polluted sediments developed abnormal brood plate setae. In contrast, while brood production was lower in females exposed to U. lactuca than on the control sediment, there was no significant difference between the two groups in the number of females that developed abnormal brood plates.

The effects of low doses of waste crankcase oil on Melita nitida Smith (Crustacea: Amphipoda)

Abstract Petroleum and petroleum byproducts are significant contaminants of marine coastal sediments. Their detrimental effects on marine species have been amply demonstrated after oil spills. However, less is known about the effects of lower doses of oil continually entering nearshorc systems from human activities. The present study provides evidence that relatively low doses of waste crankcase oil (WCCO), the predominant petroleum product in runoff and combined sewer overflow discharges, induces measurable sublethal morphological changes in the amphipod Melita nitida Smith, an epibenthic estuarine species. Adults were exposed to 1, 10, and 100 ppm WCCO mixed in sediments. Adult male and female survivorship was not reduced by exposure to these doses. Juveniles maintained at 1 and 10 ppm survived but juveniles maintained at 100 ppm died within 2 days of emergence from the female. Reproductive females developed abnormal oostegite setae in WCCO. The proportion of females developing abnormalities was directly correlated with the concentration of the WCCO.

Liver lesions in winter flounder (Pseudopleuronectes americanus) from Jamaica Bay, New York: Indications of environmental degradation

Liver sections of winter flounder (Pseudopleuronectes americanus) collected from Jamaica Bay and Shinnecock Bay, New York, in 1989, were examined microscopically to determine the pervasiveness of liver lesions observed previously in Jamaica Bay winter flounder. Neoplastic lesions were not detected in fish from Jamaica Bay or the Shinnecock Bay reference site. Twenty-two percent of Jamaica Bay winter flounder examined (n=103) had unusual vacuolization of hepatocytes and biliary pre-ductal and ductal cells (referred to hereafter as the vacuolated cell lesion). The lesion, identical to that found in 25% of Jamaica Bay winter flounder examined in 1988, has previously been identified in fishes taken from highly polluted regions of the Atlantic coast (e.g., Boston Harbor, Massachusetts, and Black Rock Harbor, Connecticut). Prevalence of the vacuolated cell lesion in winter flounder from Jamaica Bay was significantly greater (p<0.0001) than in 102 specimens collected from Shinnecock Bay. Current scientific literature indicates vacuolated hepatocytes and cholangiocytes are chronically injured and that the extent of their deformity is consistent with the action of a hepatotoxicant. The high prevalence of vacuolated hepatocytes in Jamaica Bay winter flounder and absence of the lesion in flounder from reference sites strongly supports the hypothesis that this impairment is a manifestation of a toxic condition in at least some portions of Jamaica Bay.

Phytosociological analysis of restored and managed grassland habitat within an urban national park

Floyd Bennett Field (FBF), 579 ha in extent, is a division of Gateway National Recreation Area. It is the site of a former airfield, constructed by filling salt marshes with dredged materials. Except for the portion known locally as the “North Forty,” all sections of FBF have been cut over to maintain low vegetation. A grassland management plan (GRAMP) for 165 ha was initiated in 1986, to maintain habitats for open-country birds. Over the next few years, encroaching woody vegetation was removed manually and mechanically from the management area. Since then, it has been maintained as a grassland and receives annual mowing, as well as continued manual removal of the larger woody sprouts.A portion of the GRAMP management area (III) was selected for intensive study of vegetation composition. A grid system was created and vegetation cover was estimated in 127, 1 m × 1 m quadrats. The quadrats were subjected to cluster analysis (CA). Eleven clusters were recognized. These clusters were treated as “plant associations.” The following types were distinguished: (native) little bluestem–dewberry grassland, six-weeks fescue annual grassland, a grass marsh, a rush marsh, a switchgrass dry grassland, and a deer-tongue panicgrass grassland; (exotic) mugwort herbland, oriental bittersweet-Japanese honeysuckle vineland, Kentucky bluegrass-mixed grassland, Japanese knotweed tall herbland, and spotted knapweed-common St. Johnswort herbland. The little bluestem–dewberry association accounted for nearly half of all quadrats; six subclusters were recognized. The plant associations determined by CA were compared with plant lists compiled during traverses of all of the map categories in the six GRAMP Areas (I, II, III, IV, V, VI). A table was created to relate the quantitative data of the plant associations to the appropriate map categories. A nonmetric multidimensional scaling ordination (NMDS) was performed on the quadrat data. Finally, the plant associations were compared with those described in the literature of local vegetation studies. The mowing program has been effective in decreasing woody plant cover and has permitted the invasion of a few taxa into monospecific communities, but attendant disturbance of the substrate is likely to cause an increase in exotic plant taxa. As earlier studies noted, mowing has caused the increase in cover of sod-forming grass, and bare ground has virtually disappeared in the managed area. This has negative implications for the maintenance of those grassland bird species that require open ground for nesting.

Questioning Ecosystem Assessment and Restoration Practices in a Major Urban Estuary： Perpetuating Myths of Degradation in Spite of the Facts

The Jamaica Bay ecosystem is a dichotomy. It encompasses more than 12,000 acres of coastal estuarine marshes and an ecological diversity rivaling any coastal environment in the world. It is considerably altered, and is affected by a variety of ecological insults directly related to the fact that more than 14 million people live in its vicinity. Environmental protection institutions responded to the challenge of protecting the bay, surrounding wetlands and recreational benefits by addressing the increasing load of contaminants into the ecosystem. Billions of dollars have been spent during the past five decades on restoration attempts, including upgrading wastewater treatment plantsand the closure of three major sanitary landfills. Even with the curtailment of untreated wastewater release and ending periodic dredging and filling programs, all activities that are necessary processes in maintaining an urban harbor, the Jamaica Bay ecosystem has reached a point where many believe it to be unrecoverable, requiring massive infusions of restoration dollars. This categorization has been perpetuated based on questionable data (the “myths”) that, when investigated in rigorous scientific detail, prove to be unsubstantiated. In this paper, the origin of these myths and the scientific investigation that dispel them are discussed.