Simple broodstock management to control indirect selection and inbreeding: Indian carp example

Following a survey of the important traits of Indian carp broodstock at some southern Indian hatcheries, it was found that the broodstock selection was size selective, exerting strong, negative selection of prematuration growth rate and positive selection on age at first maturation. This meant that the hatchery bred inadvertently slower growing and later maturing individuals. Details are given of approaches to avoid such negative selection and minimize inbreeding.

Broodstock management status and some suggestions to control negative selection and inbreeding in hatchery stocks in Bangladesh

The freshwater river systems and floodplains of Bangladesh are the breeding grounds for 13 endemic species of carps and barbs and a large number of other fish species, including a number of exotic carps and other species that have been introduced for aquaculture. Since 1967, breeding of endemic and exotic aquaculture species for seed producton through hypophysation techniques has become a common practice. The paper describes the present status of broodstock management, identifies problems, and suggests some guidelines to control negative selection and inbreeding in hatchery stocks in Bangladesh.

Selection and application of a suitable sampling method for quantitative and qualitative evaluation of lab-lab

Milkfish and prawn pond operation in the Philippines is often associated with lab-lab culture. Lab-lab is a biological complex of blue-green algae, diatoms, bacteria and various animals which form a mat at the bottom of nursery ponds or floating patches along the margins of ponds. This complex is considered the most favorable food of milkfish in brackishwater ponds. Variations in the quantity and quality of lab-lab between and within areas of a 1,000 sq. m. pond was determined over 2 culture periods (6 month duration) and the applicability and suitability of stratified random sampling as a method of sampling lab-lab was evaluated.

Characterization of the benthos, marine debris and bottom fish at Gray’s Reef National Marine Sanctuary

Executive Summary: Baseline characterization of resources is an essential part of marine protected area (MPA) management and is critical to inform adaptive management. Gray’s Reef National Marine Sanctuary (GRNMS) currently lacks adequate characterization of several key resources as identified in the 2006 Final Management Plan. The objectives of this characterization were to fulfill this need by characterizing the bottom fish, benthic features, marine debris, and the relationships among them for the different bottom types within the sanctuary: ledges, sparse live bottom, rippled sand, and flat sand. Particular attention was given to characterizing the different ledge types, their fish communities, and the marine debris associated with them given the importance of this bottom type to the sanctuary. The characterization has been divided into four sections. Section 1 provides a brief overview of the project, its relevance to sanctuary needs, methods of site selection, and general field procedures. Section 2 provides the survey methods, results, discussion, and recommendations for monitoring specific to the benthic characterization. Section 3 describes the characterization of marine debris. Section 4 is specific to the characterization of bottom fish. Field surveys were conducted during August 2004, May 2005, and August 2005. A total of 179 surveys were completed over ledge bottom (n=92), sparse live bottom (n=51), flat sand (n=20), and rippled sand (n=16). There were three components to each field survey: fish counting, benthic assessment, and quantification of marine debris. All components occurred within a 25 x 4 m belt transect. Two divers performed the transect at each survey site. One diver was responsible for identification of fish species, size, and abundance using a visual survey. The second diver was responsible for characterization of benthic features using five randomly placed 1 m2 quadrats, measuring ledge height and other benthic structures, and quantifying marine debris within the entire transect. GRNMS is composed of four main bottom types: flat sand, rippled sand, sparsely colonized live bottom, and densely colonized live bottom (ledges). Independent evaluation of the thematic accuracy of the GRNMS benthic map produced by Kendall et al. (2005) revealed high overall accuracy (93%). Most discrepancies between map and diver classification occurred during August 2004 and likely can be attributed to several factors, including actual map or diver errors, and changes in the bottom type due to physical forces. The four bottom types have distinct physical and biological characteristics. Flat and rippled sand bottom types were composed primarily of sand substrate and secondarily shell rubble. Flat sand and rippled sand bottom types were characterized by low percent cover (0-2%) of benthic organisms at all sites. Although the sand bottom types were largely devoid of epifauna, numerous burrows indicate the presence of infaunal organisms. Sparse live bottom and ledges were colonized by macroalgae and numerous invertebrates, including coral, gorgonians, sponges, and “other” benthic species (such as tunicates, anemones, and bryozoans). Ledges and sparse live bottom were similar in terms of diversity (H’) given the level of classification used here. However, percent cover of benthic species, with the exception of gorgonians, was significantly greater on ledge than on sparse live bottom. Percent biotic cover at sparse live bottom ranged from 0.7-26.3%, but was greater than 10% at only 7 out of 51 sites. Colonization on sparse live bottom is likely inhibited by shifting sands, as most sites were covered in a layer of sediment up to several centimeters thick. On ledge bottom type, percent cover ranged from 0.42-100%, with the highest percent cover at ledges in the central and south-central region of GRNMS. Biotic cover on ledges is influenced by local ledge characteristics. Cluster analysis of ledge dimensions (total height, undercut height, undercut width) resulted in three main categories of ledges, which were classified as short, medium, and tall. Median total percent cover was 97.6%, 75.1%, and 17.7% on tall, medium, and short ledges, respectively. Total percent cover and cover of macroalgae, sponges, and other organisms was significantly lower on short ledges compared to medium and tall ledges, but did not vary significantly between medium and tall ledges. Like sparse live bottom, short ledges may be susceptible to burial by sand, however the results indicate that ledge height may only be important to a certain threshold. There are likely other factors not considered here that also influence spatial distribution and community structure (e.g., small scale complexity, ocean currents, differential settlement patterns, and biological interactions). GRNMS is a popular site for recreational fishing and boating, and there has been increased concern about the accumulation of debris in the sanctuary and potential effects on sanctuary resources. Understanding the types, abundance, and distribution of debris is essential to improving debris removal and education efforts. Approximately two-thirds of all observed debris items found during the field surveys were fishing gear, and about half of the fishing related debris was monofilament fishing line. Other fishing related debris included leaders and spear gun parts, and non-gear debris included cans, bottles, and rope. The spatial distribution of debris was concentrated in the center of the sanctuary and was most frequently associated with ledges rather than at other bottom types. Several factors may contribute to this observation. Ledges are often targeted by fishermen due to the association of recreationally important fish species with this bottom type. In addition, ledges are structurally complex and are often densely colonized by biota, providing numerous places for debris to become stuck or entangled. Analysis of observed boat locations indicated that higher boat activity, which is an indication of fishing, occurs in the center of the sanctuary. On ledges, the presence and abundance of debris was significantly related to observed boat density and physiographic features including ledge height, ledge area, and percent cover. While it is likely that most fishing related debris originates from boats inside the sanctuary, preliminary investigation of ocean current data indicate that currents may influence the distribution and local retention of more mobile items. Fish communities at GRNMS are closely linked to benthic habitats. A list of species encountered, probability of occurrence, abundance, and biomass by habitat is provided. Species richness, diversity, composition, abundance, and biomass of fish all showed striking differences depending on bottom type with ledges showing the highest values of nearly all metrics. Species membership was distinctly separated by bottom type as well, although very short, sparsely colonized ledges often had a similar community composition to that of sparse live bottom. Analysis of fish communities at ledges alone indicated that species richness and total abundance of fish were positively related to total percent cover of sessile invertebrates and ledge height. Either ledge attribute was sufficient to result in high abundance or species richness of fish. Fish diversity (H`) was negatively correlated with undercut height due to schools of fish species that utilize ledge undercuts such as Pareques species. Concurrent analysis of ledge types and fish communities indicated that there are five distinct combinations of ledge type and species assemblage. These include, 1) short ledges with little or no undercut that lacked many of the undercut associated species except Urophycis earlii ; 2) tall, heavily colonized, deeply undercut ledges typically with Archosargus probatocephalus, Mycteroperca sp., and Pareques sp.; 3) tall, heavily colonized but less undercut with high occurrence of Lagodon rhomboides and Balistes capriscus; 4) short, heavily colonized ledges typically with Centropristis ocyurus, Halichoeres caudalis, and Stenotomus sp.; and 5) tall, heavily colonized, less undercut typically with Archosargus probatocephalus, Caranx crysos and Seriola sp.. Higher levels of boating activity and presumably fishing pressure did not appear to influence species composition or abundance at the community level although individual species appeared affected. These results indicate that merely knowing the basic characteristics of a ledge such as total height, undercut width, and percent cover of sessile invertebrates would allow good prediction of not only species richness and abundance of fish but also which particular fish species assemblages are likely to occur there. Comparisons with prior studies indicate some major changes in the fish community at GRNMS over the last two decades although the causes of the changes are unknown. Species of interest to recreational fishermen including Centropristis striata, Mycteroperca microlepis, and Mycteroperca phenax were examined in relation to bottom features, areas of assumed high versus low fishing pressure, and spatial dispersion. Both Mycteroperca species were found more frequently when undercut height of ledges was taller. They often were found together in small mixed species groups at ledges in the north central and southwest central regions of the sanctuary. Both had lower mode size and proportion of fish above the fishery size limit in heavily fished areas of the sanctuary (i.e. high boat density) despite the presence of better habitat in that region. Black sea bass, C. striata, occurred at 98% of the ledges surveyed and appeared to be evenly distributed throughout the sanctuary. Abundance was best explained by a positive relationship with percent cover of sessile biota but was also negatively related to presence of either Mycteroperca species. This may be due to predation by the Mycteroperca species or avoidance of sites where they are present by C. striata. Suggestions for monitoring bottom features, marine debris, and bottom fish at GRNMS are provided at the end of each chapter. The present assessment has established quantitative baseline characteristics of many of the key resources and use issues at GRNMS. The methods can be used as a model for future assessments to track the trajectory of GRNMS resources. Belt transects are ideally suited to providing efficient and quantitative assessment of bottom features, debris, and fish at GRNMS. The limited visibility, sensitivity of sessile biota, and linear nature of ledge habitats greatly diminish the utility of other sampling techniques. Ledges should receive the bulk of future characterization effort due to their importance to the sanctuary and high variability in physical structure, benthic composition, and fish assemblages. (PDF contains 107 pages.)

Improving coastal livelihoods through sustainable aquaculture practices in Hon Mun marine protected area, Nha Trang Bay, Vietnam: a report to the collaborative APEC Grouper Research and Development Network

This case study describes the present status and trends, and provides recommendations for the improvement of aquatic resources management within Hon Mun Marine Protected Area (MPA), Nha Trang Bay, Khanh Hoa Province, Vietnam. The case study also evaluates options for improving the livelihoods of local villagers through the development of ecologically sustainable aquaculture and fisheries, which include diversification following careful selection and trial of appropriate culture species, and application of “best practice” culture methods. (Pdf contains 43 pages).

Fishery management plans and the development of artisanal fisheries in Nigeria: a review

Management of natural resources all over the world is of paramount importance to their sustainability in developing countries like Nigeria, there is less emphasis on proper management especially of fishery and other aquatic resources due to lack of sensitization and enlightenment of the rural dwellers who are closer to such natural resources. The main thrust of this review is to examine the management plans for Nigerian freshwater bodies (rivers and lakes) and the impact of such plans on the artisanal fisheries development in Nigeria. From the on-shelf information gathered there is scarcity of information on the management of Nigerian freshwater body's information available indicates that there is the traditional fisheries management and the government legal approach in form of fisheries Laws and Regulations. However, these management techniques are poorly carried out since there is a poor follow-up. Appreciable impact of fisheries management introduced on Kanji Lake by the Nigerian-German Kanji Lake Fisheries Promotion Project (NGKLFPP) between 1993 and 2001 proves worthwhile as this introduced some management measures such as implementation of fisheries Laws and Regulations, the ban of obnoxious fishing methods, introduction of fishing license, constitution of a management unit and appointment of liaison fishermen. Within the operative years of the project a lot of success was achieved and it is recommended that the approach in Kainji should be replicated in other freshwater bodies in Nigeria to alleviate poverty in the rural poor fishing communities

An annotated bibliography of aquatic sediment traps and trapping methods

This annotated bibliography is intended to give as reasonably complete a review of the existing literature as possible, and to offer some practical guidance in the selection and operation of sediment traps in future monitoring programmes.

Population dynamics and stock assessment of Koth (Otolithoides biauritus Cantor, 1850) along the north-west coast of India

MSY, growth, selection and mortality parameters of Otolithoides biauritus have been worked out from data collected by MFV Saraswati of CIFE, and length frequency data from Ferry Wharf, Sasson dock, and Versova fish landing centres of Bombay. Values of L infinity, K, and t omicron obtained from length frequency study are 1572 mm, 0.2633/yr and 0.0289 yr respectively, and of weight growth parameters are W infinity = 10067 g, K = 0.03904/yr and t omicron = 0.0137 yr. Selection parameters are L + 150 mm, t sub(r) + 0.4167 yr lc + 240 mm and t omicron = 0.6367 yr. Selection factor (K) for codent worked out to be 12. Based on Z = 0.6486, the MSY of O. biauritus off northwest coast of India is assessed as 1,802 tons which is slightly higher than the current catch level of 1,634 tons.

Study on some biological and feeding factors of spined loach Cobitis taenia from the Babolrud, Talar and Siahrud Rivers

Spined loach, Cobitis taenia, is a predominant fish in the river systems of the southern Caspian Sea basin. Although there is evidence of the geographical divergence of this taxon, but no information is available on morphological differences within the species populations. This study was designed to evaluate some biological factors including; morphometric and meristic characters, length-weight, age-growth, condition factor, diet, reproduction, variation and differentiation, in the Babolrud, Talar and Siahrud Rivers in south of the Caspian Sea basin. Age, sex ratio, fecundity, ova diameter and gonadosomatic index were estimated. Also, regression analyses was tested the relation between fecundity and fish length, weight, gonad weight, and also age. Totally 858 fish of which 721 were matures, were collected from these rivers by electrofishing. 37 morphometric characters, 9 meristic characters and 78 truss network system characters were estimated. Resulats of DFA analysis based on data of morphometric and meristic showd that these populations are highly (94.5%) varios from each other. In discriminate function analysis, the proportion of individuals correctly classified into their original groups was 61%, 65.4% and 86.5% for upstream and downstream, respectively. Clustering based on Euclidean distances among groups of centroids using an UPGMA and also principal component analysis’ results for morphometric data indicated that these populations from these three rivers were clearly distinct from each other. Regression equations between length and weight in these three populations were significantly different from Folton factor (b=3), that showed the fish has a negative Alometric growth process. Condition factor was estimated between 0.8912 to 1.2736 and 0.8131 to 1.4489 for males and females, respectively. Sex ratio (female: male) in these populations was 1.2816:1. The difference between the number of females and males was significant and females were more than males. The female and male specimens reach maturity by Tl more than 40 and 30 mm and at the age of 2+ and 1+, respectively. The mean of ova diameter was 0.5824±0.2882. The spawning took place from May to late July, at the water temperature from 18.7 to 24.0°C. The GSI values average at the beginning of the reproduction period was about 9%, with ranged from 2 to 26% in ripe mature females. The absolute and relative fecundity were 2109±792 and 579±208 respectively. The absolute fecundity was significantly related to body weight and gonads weight. Based on the pattern of gonado-somatic index, it was concluded that this fish has prolong active reproductive period, which is a type of adaptation by short-lived small fishes to environmental conditions. The macroscopic and histological results showed that the female and male have 5 and 4 stages in their maturation process, respectively. The RLG index was about 0.4732, which showed the fish is a carnivorous species. Significant difference was observed between fishes with different length and diet. The main foods of the fish were Trichoptera, Chironomidae larvae and Ephemeroptera which were their prefered food as well, however it was estimated that the food selection and diet are affected by environmental conditions.

Characterization of genetic biodiversity of Nile perch, Lates niloticus, Tilapiines, Haplochromine flock and Ningu (Labeo victorianus) in the Victoria Lake Basin: an overview

Genetic biodiversity is the vaflatlOn among individuals within and between units of interbreeding individuals (populations) of a species. It includes inheritable and transmittable differences that occur between individuals andlor popuhitions of a given species through reproductive interaction. There exists enormous variability among individuals andlor populations of a species for most living organisms, and most of this variation is inheritable. differences among individuals arise through mutation and via recombination of genes during meiosis. These ifferences are then transmitted to successive generations through sexual reproduction and maintained in the populations through processes such as natural selection and genetic drift. Unfortunately much of this variation is normally threatened and often in danger of extinction because most focus in conservation of natural resources is put at saving species or habitats than varieties or strains of a species

Legal consideration on Convention for the Prevention of Dumping of Wastes and Other Matter (at sea) and assessment of its implementation in Iran (The London [dumping] Convention)

Making use of sea, as a place for dumping of wastes and other materials from human activities wasn’t forbidden before creation of the convention on the prevention of marine pollution by dumping of wastes and other matters (London Convention). Therefore, industrial countries, without any specific consideration, were dumping their wastes into the world’s seas. Many years and before the beginning of rapid development of industry, the great self- purification of seas were preventing some of discharging problems. But gradually, the increase of industrial development activities, exceeded the production of wastes and other matters, and this led to the misuse of world’s seas and oceans as a dump site. One of the most important consequences of 1972 Stockholm World Conference was to focusing world attention on threats have jeopardized marine environment balance. World countries` leaders committed in Stockholm to begin protecting the environment. Finally, this movement at marine environment section led to the creation of London Convention in the same year. London Convention was concluded for cooperating between countries at December 29, 1972 to promote effective control of all marine environment polluting resources and to prevent marine pollution by dumping wastes and other matters. Then it was opened for signature to other countries. At last, after 15 states signature, this convention was entered in to force at August 30.1975. Ratification and execution of London Convention resulted in coordinated performance of countries in marine waste management. Common actions with supports and cooperation of different international, regional, governmental and non-governmental organizations and agencies prevent marine pollution by dumping of wastes and other matters. Due to the importance of wastes in our marine and coastal areas, investigation of the performance of London Convention can identify the lack of regulations and lack of regulation supports about marine pollution prevention by dumping of wastes and other matters in Iran. Considering this issue, proper protection of seas will be achieved. London Convention has been studied here to achieve intended purposes. In first chapter, generalities about marine environment, including the importance and necessity of marine environment protection, with the focus on some internal and international resources of environmental law accompanying with marine pollution and its recourses, and finally, due to the study theme, dumping of wastes and other matters at seas with its impacts have been investigated .In the section of international measures, a brief history of marine pollution and marine environment international law with international law framework, exclusively for controlling of wastes and other material discharge at seas and oceans has been reviewed. In second chapter, obligations, amendments, and annexes of London Convention have been investigated and classified. The obligations have been categorized in to legal obligations and technical and organizational obligations. In former section, subject ,purpose, territory, exceptions, rights and duties of parties, convention amendments,… and in latter, special requirements for wastes assessment, determination of pollutants` permissible limit, site selection and type of discharge selection, design principles for marine environment quality monitoring program, and discharge license issuance mechanism have been studied. In third chapter, due to the examination of convention performance in Iran, the internal law system for marine environment conservation and its pollution has been mentioned in detail. Considering this, two issues have been compared .firstly, convention obligations with regional treaties that Iran as a party to them and secondly, Iranian internal law there of .Finally, common and different aspects of these issues have been determined. At last, recommendations and strategies for convention enforcement and conformity of its obligations with internal regulations have been presented. Furthermore, translation of convention English text has been reviewed and its protocol has been translated.