Baseline assessment of Guánica Bay, Puerto Rico in support of watershed restoration

Guánica Bay is a major estuary on the southwest coast of Puerto Rico. Significant coral reef ecosystems are present outside the bay. These valuable habitats may be impacted by transport of sediments, nutrients and contaminants from the watershed, through the bay and into the offshore waters. The National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Coastal Ocean Science (NCCOS), in consultation with local and regional experts, conducted an interdisciplinary assessment of coral reef ecosystems, contaminants, sedimentation rates and nutrient distribution patterns in and around Guánica Bay. This work was conducted using many of the same protocols as ongoing monitoring work underway elsewhere in the U.S. Caribbean and has enabled comparisons among coral reef ecosystems between this study and other locations in the region. This characterization of Guánica marine ecosystems establishes benchmark conditions that can be used for comparative documentation of future change, including possible negative outcomes due to future land use change, or improvement in environmental conditions arising from management actions. This report is organized into six chapters that represent a suite of interrelated studies. Chapter 1 provides a short introduction to the study area. Chapter 2 is focused on biogeographic assessments and benthic mapping of the study area, including new surveys of fish, marine debris and reef communities on hardbottom habitats in the study area. Chapter 3 quantifies the distribution and magnitude of a suite of contaminants (e.g., heavy metals, PAHs, PCBs, pesticides) in both surface sediments and coral tissues. Chapter 4 presents results of sedimentation measurements in and outside of the bay. Chapter 5 examines the distribution of nutrients in in the bay, offshore from the bay and in the watershed. Chapter 6 is a brief summary discussion that highlights key findings of the entire suite of studies.

Studies on the use of alginates in frozen fishery products

Results of preliminary studies on the use of sodium alginate as a protective coating for fishery products showed that several varieties of fishes and shell fish had better keeping qualities when coated with sodium alginate.

Estimation of maximum sustainable yield (MSY) of hilsa (Tenualosa ilisha Ham.) in the Meghna river of Bangladesh

MSY per recruit of Tenualosa ilisha in the Meghna river was predicted as 112 g per recruit at the F(msy)=0.6/yr and at T(c)=0.6/yr. But Y/R=95 g per recruit was obtained at the existing fishing level, F=1.14/yr and at T(c)=0.6/yr. Existing F level was nearly double than the F(msy) level. Fishing pressure should be reduced immediately from F=1.14/yr to F(msy)=0.6/yr. F(msy)=1.14/yr was the same at first capture, T(c)=1.0, 1.2 and 1.4/yr, and MSY could be obtained as 142 g, 162 g and 176 g per recruit respectively. It is easier to change the first capture age (Tc) rather than changing off level. So, hilsa fishery manager may adopt F(msy)=1.14/yr while age at first capture must be increased from T(c)=0.6/yr (3 cm size group) to T(c)=1.4/yr (25 cm size group), by which 1.8 times production could be increased than the present production. MSY also possible to obtain as 201 g and 210 g per recruit at F(msy)=2.0/yr and 4.0/yr at T(c)=1.7/yr and 1.9/yr respectively. Under both the situations, hilsa production could be increased 2 times than the present production. To obtain the MSY=210 g per recruit the fishing level could be increased up to F=4.0/yr at T(c)=1.9/yr (34 cm size group). Economic point of view, hilsa fishery managers may choose to obtain the economic MSY as 201 g per recruit at F(msy)=2.0/yr and T(c)=1.7yr (31 cm size group) in the Meghna river of Bangladesh.

Feeding metabolism in an Indian major carp (Catla catla Lin.) fed on different protein diets

Feeding metabolism in an Indian major carp, Catla catla fingerlings of 10.8+0.56g was investigated in a flow-through water recirculating system. The metabolic energy loss in resting metabolism and feeding metabolism were determined by the indirect method of oxygen consumption followed by multiplication by suitable oxycalorific coefficient. This was done in four metabolic chambers of a respirometer system. Ten fish fingerlings of mean total weight of 109.5, 110.4 and 112.8g/chambers respectively each in two experimental runs of three treatments a, b and c were used. The mean resting metabolic rate during unfed condition showed no significant variation in different treatments. The fish in three treatments a, b and c fed on diets containing 28, 33 and 38% crude protein had significantly different (p<0.05) post-fed SDA magnitude of 497.7, 638.7 and 735.5 mgO2/chamber/day having an equivalent energy loss of 12.68, 14.68 and 15.86 KJ respectively. The SDA co-efficient in three treatments a, b and c were 14.95, 19.00 and 22.36% respectively whereas, respiratory energy - 'R' as % of mean total ingested energy in three treatments were 26.93, 31.17 and 34.74% respectively showing a significant increase (p<0.05) with increase of protein. Feeding metabolism in an Indian major carp (Catla catla Lin.) fed on different protein diets.

Studies on smoking of eel fillets

A procedure has been worked out to (hot) smoke eel fillets. Some of the important factors such as size of the fillets, brining, pre-drying, source of smoke, smoking period, final drying have been studied. Best quality of smoked product is obtained on smoking eel fillets with a mixture of coconut-husk and sag saw-dust in 1:1 proportion for 15 hours. Optimum moisture level of the final product was fixed in the range of 30 to 35% and it had a storage life of about 8 months at room temperature.

A Preliminary study of the defensive spines of some Malayan freshwater fishes

The defensive spines of fifteen Malayan freshwater fishes have been studied morphologically. The classification of spines has been slightly modified from the previous work of Fernando and Fernando (1960). They are divided into simple, denticle-bearing and venom-carrying. The simple spines are further sub-divided into single and multiple and the denticle-bearing into Bagriid and Clariid types. The latter agree morphologically with the venom-carrying spines of previously studied forms and may be a degenerate condition. Simple spines occur singly in the Cyprinidae where they are found at the anterior end of the dorsal fin. A spine of similar structure occurs in the catfish Glyptothorax. In the families Anabantidae, Cichlidae and Mastacenbelidae simple spines occur as a series. Denticle-bearing spines occur in the catfishes (Order-Nematognathi). Those having denticles on one face occur in the Bagridae, Siluridae, Sisoridae, and Akysidae. They are referred to as Bagriid type. In the other type denticles occur on the anterior and posterior faces of the spine. They are referred to as Clariid type. None of the Malayan species studied had venom-carrying spines and they are unlikely to be found in the freshwater species. The functioning of the defensive mechanism whose morphological bases are spines is discussed and the relation between the size and habitat on the effectiveness of the spines is mentioned. The evolution of defensive spines is discussed briefly.