Assessment of natural resource conditions in and adjacent to Dry Tortugas National Park

This project characterized and assessed the condition of coastal water resources in the Dry Tortugas National Park (DRTO) located in the Florida Keys. The goal of the assessment was to: (1) identify the state of knowledge of natural resources that exist within the DRTO, (2) summarize the state of knowledge about natural and anthropogenic stressors and threats that affected these resources, and (3) describe strategies being implemented by DRTO managers to meet their resource management goals. The park, located in the Straits of Florida 113 km (70 miles) west of Key West, is relatively small (269 square kilometers) with seven small islands and extensive shallow water coral reefs. Significant natural resources within DRTO include coastal and oceanic waters, coral reefs, reef fisheries, seagrass beds, and sea turtle and bird nesting habitats. This report focuses on marine natural resources identified by DRTO resource managers and researchers as being vitally important to the Tortugas region and the wider South Florida ecosystem. Selected marine resources included physical resources (geology, oceanography, and water quality) and biological resources (coral reef and hardbottom benthic assemblages, seagrass and algal communities, reef fishes and macro invertebrates, and wildlife [sea turtles and sea-birds]). In the past few decades, some of these resources have deteriorated because of natural and anthropogenic factors that are local and global in scale. To meet mandated goals (Chapter 1), resource managers need information on: (1) the types and condition of natural and cultural resources that occur within the park and (2) the stressors and threats that can affect those resources. This report synthesizes and summarizes information on: (1) the status of marine natural resources occurring at DRTO; and (2) types of stressors and threats currently affecting those resources at the DRTO. Based on published information, the assessment suggests that marine resources at DRTO and its surrounding region are affected by several stressors, many of which act synergistically. Of the nine resource components assessed, one resource category – water quality – received an ecological condition ranking of "Good"; two components – the nonliving portion of coral reef and hardbottom and reef fishes – received a rating of "Caution"; and two components – the biotic components of coral reef and hardbottom substrates and sea turtles – received a rating of "Significant concern" (Table E-1). Seagrass and algal communities and seabirds were unrated for ecological condition because the available information was inadequate. The stressor category of tropical storms was the dominant and most prevalent stressor in the Tortugas region; it affected all of the resource components assessed in this report. Commercial and recreational fishing were also dominant stressors and affected 78% of the resource components assessed. The most stressed resource was the biotic component of coral reef and hardbottom resources, which was affected by 76% of the stressors. Water quality was the least affected; it was negatively affected by 12% of stressors. The systematic assessment of marine natural resources and stressors in the Tortugas region pointed to several gaps in the information. For example, of the nine marine resource components reviewed in this report, the living component of coral reefs and hardbottom resources had the best rated information with 25% of stressor categories rated "Good" for information richness. In contrast, the there was a paucity of information for seagrass and algal communities and sea birds resource components.

Atlas of the shallow-water benthic habitats of American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands

The National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS) initiated a coral reef research program in 1999 to map, assess, inventory, and monitor U.S. coral reef ecosystems (Monaco et al. 2001). These activities were implemented in response to requirements outlined in the Mapping Implementation Plan developed by the Mapping and Information Synthesis Working Group (MISWG) of the Coral Reef Task Force (CRTF) (MISWG 1999). As part of the MISWG of the CRTF, NOS' Biogeography Branch has been charged with the development and implementation of a plan to produce comprehensive digital coral-reef ecosystem maps for all U.S. States, Territories, and Commonwealths within five to seven years. Joint activities between Federal agencies are particularly important to map, research, monitor, manage, and restore coral reef ecosystems. In response to the Executive Order 13089 and the Coral Reef Conservation Act of 2000, NOS is conducting research to digitally map biotic resources and coordinate a long-term monitoring program that can detect and predict change in U.S. coral reefs, and their associated habitats and biological communities. Most U.S. coral reef resources have not been digitally mapped at a scale or resolution sufficient for assessment, monitoring, and/or research to support resource management. Thus, a large portion of NOS' coral reef research activities has focused on mapping of U.S. coral reef ecosystems. The map products will provide the fundamental spatial organizing framework to implement and integrate research programs and provide the capability to effectively communicate information and results to coral reef ecosystem managers. Although the NOS coral program is relatively young, it has had tremendous success in advancing towards the goal to protect, conserve, and enhance the health of U.S. coral reef ecosystems. One objective of the program was to create benthic habitat maps to support coral reef research to enable development of products that support management needs and questions. Therefore this product was developed in collaboration with many U.S. Pacific Territory partners. An initial step in producing benthic habitat maps was the development of a habitat classification scheme. The purpose of this document is to outline the benthic habitat classification scheme and protocols used to map American Samoa, Guam and the Commonwealth of the Northern Mariana Islands. Thirty-two distinct benthic habitat types (i.e., four major and 14 detailed geomorphological structure classes; eight major and 18 detailed biological cover types) within eleven zones were mapped directly into a geographic information system (GIS) using visual interpretation of orthorectified IKONOS satellite imagery. Benthic features were mapped that covered an area of 263 square kilometers. In all, 281 square kilometers of unconsolidated sediment, 122 square kilometers of submerged vegetation, and 82.3 square kilometers of coral reef and colonized hardbottom were mapped.

Distribution and abundance of humpback whales (Megaptera novaeangliae) and other marine mammals off the northern Washington coast

We examined the summer distribution of marine mammals off the northern Washington coast based on six ship transect surveys conducted between 1995 and 2002, primarily from the NOAA ship McArthur. Additionally, small boat surveys were conducted in the same region between 1989 and 2002 to gather photographic identification data on humpback whales (Megaptera novaeangliae) and killer whales (Orcinus orca) to examine movements and population structure. In the six years of ship survey effort, 706 sightings of 15 marine mammal species were made. Humpback whales were the most common large cetacean species and were seen every year and a total of 232 sightings of 402 animals were recorded during ship surveys. Highest numbers were observed in 2002, when there were 79 sightings of 139 whales. Line-transect estimates for humpback whales indicated that about 100 humpback whales inhabited these waters each year between 1995 and 2000; in 2002, however, the estimate was 562 (CV= 0.21) whales. A total of 191 unique individuals were identified photographically and mark recapture estimates also indicated that the number of animals increased from under 100 to over 200 from 1995 to 2002. There was only limited interchange of humpback whales between this area and feeding areas off Oregon and California. Killer whales were also seen on every ship survey and represented all known ecotypes of the Pacific Northwest, including southern and northern residents, transients, and offshore-type killer whales. Dall’s porpoise (Phocoenoides dalli) were the most frequently sighted small cetacean; abundance was estimated at 181−291 individuals, except for 2002 when we observed dramatically higher numbers (876, CV= 0.30). Northern fur seals (Callorhinus ursinus) and elephant seals (Mirounga angustirostris) were the most common pinnipeds observed. There were clear habitat differences related to distance offshore and water depth for different species.

Seasonal resolution of laminated sediments in Santa Barbara Basin: its significance in paleoclimatic studies

Sediments in Santa Barbara Basin contain microfossil and sedimentological information that allows reconstruction of major features of the California Current such as water temperature, strength of upwelling, and productivity. ... Until now, investigations of Santa Barbara Basin sediments have utilized analytical techniques that could not resolve seasonal laminae, permitting annual resolution of variations in sediment composition and structure only. ... Based on a successful technique for preparation of epoxy-embedded and highly polished thin-sections that permit economical optical and electron microscope evaluation of laminated sequences, it is our long-term goal to reconstruct, with unprecedented detail, the history of sedimentation processes in the Santa Barbara Basin by developing ultra-high-resolution time series of biotic and detrital proxies.

Diseases and parasites of penaeid prawns of India: a short review

The diseases caused by bacteria, fungi, protozoa and metazoa as well as by other biotic and abiotic agents reported in the penaeid prawns of India are reviewed.

Phytoplankton communities of a floodplain lake of the Brahmaputra River basin, Upper Assam

Phytoplankton (52 species; Bacillariophyceae>Chlorophyceae>Cyanophyceae> Euglenophyceae=Dinophyceae) of Samuajan beel, a tropical floodplain lake, registered identical mean annual richness (30+4 species) in littoral and limnetic regions and depicted 33.3-77.2% and 31.4-81.1% community similarities respectively. Their abundance ranged between 137+54 n/l in littoral (Bacillariophyceae>Chlorophyceae) and 122 ± 45 n/l (Chlorophyceae>Bacillariophyceae) in limnetic communities, comprised about 46% of net plankton and indicated winter peaks. This study depicted moderate species diversity, high evenness and low dominance of phytoplankton; species diversity showed significant direct correlation with richness and evenness and an inverse relationship with dominance. Phytoplankton showed significant positive relationship with transparency and silicate and negative with water temperature, rainfall, chloride and nitrate. Multiple regression revealed that ten abiotic factors accounted for >80-98% of density variations of phytoplankton and the dominant groups. ANOVA depicted trends of significance in abundance of the biotic communities analysed.

Suitability of commercially available Bacillus probiotics on growth, survival and production of black tiger shrimp (Penaeus monodon Fab.)

Different forms of Bacillus probiotics was assessed in the earthen ponds on tiger shrimp (Penaeus monodon) culture. The experiment was designed with three different treatments depending on the mode of application (T1=oral probiotics; T2=spreading probiotics and T3=oral+ spreading probiotics). The shrimp was cultured for 120 days with the stocking density of 6-PL/m².Oral probiotics in the respective ponds were supplied with feeds. Whereas, spreading probiotics was applied to the pond water during pond preparation at 30, 60 and 90 days of culture period. Results of the experiment revealed that, all forms of Bacillus probiotic had effective role to keep the culture environment friendly in terms of mineralization of organic matter, nitrogen and phosphorus content in bottom sediment; holding of water transparency in a congenial state, increasing the density of planktonic biomass and boosting the THB-Vibrio ratio in water and sediment with insignificance (p>0.05) difference between different treatments. Whilst, spreading form of Bacillus pro biotic showed higher weight gain (27.58±1.18g), survival rate (70.75±8.54%) and production (1167.66±109.62 kg/ha) and expected lower FCR (1.81 ±0.06) values with significant difference (p<0.01) with others methods of application, indicated its superiority in tiger shrimp culture.

The study of ecological condition on productivity of Tajan River estuary in Mazandaran Province Caspian Sea

This project was done during a one-year period (2006-2007) with the aim of assessing and evaluating the susceptible and vulnerable habitat of Tajan River estuarine region as well as identifying its ecological features. This region consists of Tajan estuarine region as one of the sub-basins of the Caspian Sea basin which covers a surface of 2km2. In this assessment, 6 riverine estuarine and marine stations were chosen in which non-biotic parameters such as temperature, salinity, dissolved oxygen, pH and nutrients, and biotic parameters such as variation, density, plankton, primary production by chlorophyll-a. Benthos variation density, silt and the organic materials of the sediments were sampled and measured monthly. The amount of chlorophyll-a concentration and primary production showed a lot of seasonal changes at these stations which ranged from0.3 to 96 mg/m3. The results from the primary productions indicated that the eastern station of the estuary had high concentrations of chlorophyll-a during all seasons (96mg/m3). The most important and dominant planktonic groups in this region included Bacillariophyta from plankton and copepoda from zooplankton. The most important Benthos communities consisted of Driessena polymorpha.Cerastoderma lamarki in estuarine region,Chironomus plumosus in riverine region and Hypaniola sp. In marine region. Assessing the annual variation in these three riverine, estuarine and marine regions, phytoplankton with 3.1, Zooplankton with 2.7 and Benthos with 1.9 Showed the most density in the estuarine region. Assessing the annual density, phytoplanktonic (6118967 no . in m3) and zooplanktonic (7272 no . in m3) communities showed the most density in the marine region. Assessing the statistical tests showed that the estuarine and riverine regions had a significant difference in planktonic density (p<0.005) compared with the marine region. Moreover, The zeoplanktonic density in the marine region had a significant difference (p<0.005) with estuarine and riverine regions. Tooki test and one-way variance Analysis showed that in assessing the planktonic groups (p<0.005) and Benthos (p<0.005), there was a significant difference in variation index between river with estuary, and estuary with the sea. The amount of the total annual live biomass of the Benthos resource in Tajan river estuarine region was estimated 757.66 g/m2.

Past trends, present stocks and possible future state of the fisheries of the Tanzania part of the Lake Victoria

The Tanzania part of Lake Victoria is the most important single fishery resource for the country. Past fishing practice caused disparity between the relative abundance in the catches and in the available stocks by overfishing some species while under-fishing others. Preliminary studies of distribution pattern, biomass estimates, etc, as derived from bollom trawl exploratory data, and the trend of the commercial catch statistics from 1958 to 1970, suggest that many of the commercially preferred species may not have the biotic potential 10 sustain higher yields under present ecological and fishing regimes. Haplochromis and a few other fish might be the only hope. Geographic extension of fishing to deeper waters may not be very promising as species diversificarion and fish density decline with depth. To develop and manage the fisheries, make full use of the resource and ensure economic and biological perpetuation of thc fishery, the appropriate fishing strategy cannot be properly developcd overnight.

The role of ecological studies in the rational management of fish stocks

Studies on the ecology of freshwaters are basic to the rational development and management of their fisheries. and the relationships between different abiotic and biotic components of aquatic ecosystems are discussed in this paper. Examples are given of the ways in which such studies have been used to establish factors that may limit or increase yields from various Zambian waters.