Multidirectional movements of sportfish species between an estuarine no-take zone and surrounding waters of the Indian River Lagoon, Florida

We examined movement patterns of sportfish that were tagged in the northern Indian River Lagoon, Florida, between 1990 and 1999 to assess the degree of fish exchange between an estuarine no-take zone (NTZ) and surrounding waters. The tagged f ish were from seven species: red drum (Sciaenops ocellatus); black drum (Pogonias cromis); sheepshead (Archosargus probatocephalus); common snook (Centropomus undecimalis); spotted seatrout (Cynoscion nebulosus); bull shark (Carcharhinus leucas); and crevalle jack (Caranx hippos). A total of 403 tagged fish were recaptured during the study period, including 65 individuals that emigrated from the NTZ and 16 individuals that immigrated into the NTZ from surrounding waters of the lagoon. Migration distances between the original tagging location and the sites where emigrating fish were recaptured were from 0 to 150 km, and these migration distances appeared to be influenced by the proximity of the NTZ to spawning areas or other habitats that are important to specific life-history stages of individual species. Fish that immigrated into the NTZ moved distances ranging from approximately 10 to 75 km. Recapture rates for sportfish species that migrated across the NTZ boundary suggested that more individuals may move into the protected habitats than move out. These data demonstrated that although this estuarine no-take reserve can protect species from fishing, it may also serve to extract exploitable individuals from surrounding fisheries; therefore, if the no-take reserve does function to replenish surrounding fisheries, then increased egg production and larval export may be more important mechanisms of replenishment than the spillover of excess adults from the reserve into fishable areas.

Bycatch in the tuna purse-seine fisheries of the western Indian Ocean

Bycatch taken by the tuna purse-seine fishery from the Indian Ocean pelagic ecosystem was estimated from data collected by scientific observers aboard Soviet purse seiners in the western Indian Ocean (WIO) during 1986–92. A total of 494 sets on free-swimming schools, whale-shark-associated schools, whale-associated schools, and log-associated schools were analyzed. More than 40 fish species and other marine animals were recorded. Among them only two species, yellow-fin and skipjack tunas, were target species. Average levels of bycatch were 0.518 metric tons (t) per set, and 27.1 t per 1000 t of target species. The total annual purse-seine catch of yellowfin and skipjack tunas by principal fishing nations in the WIO during 1985–94 was 118,000–277,000 t. Nonrecorded annual bycatch for this period was estimated at 944–2270 t of pelagic oceanic sharks, 720–1877 t of rainbow runners, 705–1836 t of dolphinfishes, 507–1322 t of triggerfishes, 113–294 t of wahoo, 104–251 t of billfishes, 53–112 t of mobulas and mantas, 35–89 t of mackerel scad, 9–24 t of barracudas, and 67–174 t of other fishes. In addition, turtle bycatch and whale mortalities may have occurred. Because the bycatches were not recorded by some purse-seine vessels, it was not possible to assess the full impact of the fisheries on the pelagic ecosystem of the Indian Ocean. The first step to solving this problem is for the Indian Ocean Tuna Commission to establish a pro-gram in which scientific observers are placed on board tuna purse-seine and longline vessels fishing in the WIO.

Breeding of Indian major carps and common carp in semi-arid zone of Haryana under controlled environment

Vast barren lands are lying vacant in the semi-arid zone of India, which can effectively be utilised for fish farming. Experiments conducted in semi-arid conditions at Damdama indicated that it is possible to breed Indian major carps and common carp under controlled conditions of modern carps hatchery CIFE D-80 without depending on rain.

Impact of mechanisation of fisheries development in Karnataka

Karnataka, one of the maritime states on the west coast of India, has progressed quite well in marine fisheries due to its vast fisheries resources and diversification in mechanised fishing. Mechanisation programmes were started by the state from 1957-58 only. Starting with two small mechanised boats, the state has today a fishing fleet of 398 purseseiners, 731 gillnetters, 2 deepsea trawlers and about 1,500 shrimp trawlers contributing over 85% of the total marine fish landings. The marine fish production during 1987-88 up to the end of March 1988 was 1,29,659 tonnes valued at Rs.48.05 crores.

Bright prospects for Indian fisheries

Development of the Indian fisheries sector, both inland and marine, is discussed in detail, examining production trends and resource potential. Prospects for future development are also considered.

On the identification of the early developmental stages of clupeiform fishes from Indian waters

Among about 65 species of clupeiform fishes present in the seas around India, most are distributed along both the east and west coasts and have similar spawning seasons and spawning grounds. The most difficult problem experienced with regard to the identification of their early developmental stages is the overlapping sets of diagnostic features among many species within the same genus as well as among species belonging to two or more genera. From studies carried out recently, the present paper sites a few instances wherein certain subtle characters have been used for distinguishing the early developmental stages of a few allied species.

Marine pollution in the Indian Ocean: problems, prospects and perspectives

Following a brief outline of the physiography of the Indian Ocean, an examination is made of the current situation regarding contamination of the environment. Prominent marine pollutants and the consequences of the marine disposal are discussed, considering in particular oil pollution, heavy metal pollution, agricultural wastes and domestic wastes. Research activities conducted in the area investigating the levels of marine pollution are detailed, and an evaluation made of future prospects concerning the monitoring and control of pollution.

An Indian Ocean record for a porcellanid crab, Raphidopus ciliatus Stimpson, 1958

Several specimens of a porcellanid crab Raphidopus ciliatus are being reported for the first time from the northern Arabian Sea, extending the range of the species into the Indian Ocean. Specimens were found in by-catches landing at fish harbour, four specimens were recovered from stomachs of noncommercial fish, Batrachus grunniens. Salient features of the species are described. Individual variations specially noted.

A northern Indian Ocean record of a bopyrid, Parapenaeon japonica (Thielemann, 1910) parasitic on species of penaeid prawns (Penaeus)

A female of Penaeus merguiensis de Man collected from Karachi fish harbour (8 May, 1993) was with a large specimen of bopyrid in its right gill chamber. Since this was the second record (see Tirmizi and Bashir, 1973) of a bopyrid from a species other than Parapenauopsis stylifera H. Milne-Edwards the specimen was examined out of curiosity.

Impact of technology on Indian fisheries

The large increase in world output from fisheries and its increased use as food by people all over the world have been the result of successful application of newer knowledge in fisheries technology. The paper deals with some of the important fields in which modern technology has influenced the course of events in the development of Indian fisheries.

Some observations on the problem of marine timber destroying organisms of Indian coasts

In India the chief marine timber boring organisms are 2 species of Martesia, 28 species of shipworms, 4 species and a variety of Sphaeroma and 9 species of Limnoria besides bacteria and fungi. The occurrence, abundance and activity of the various species of borers show remarkable variations and fluctuations in the different harbours of India, each harbour or area having its own dominant set of species and an assemblage of less important forms. These species have their own characteristic preferences, life history and seasons of attachment and a scheme evolved for one locality may prove ineffective for another. Through a delicate and complex ecological adjustment the borers occurring in a locality have reached an interrelationship reducing interspecific and intraspecific competition. The seasons of settlement of the dominant borers in the different harbours of India are indicated. The need for a detailed biological enquiry is stressed.

Life history and behaviour of Indian prawns

Studies on life history and behaviour of prawns form an essential background for the understanding of the disposition of their fisheries and for the formulation of effective methods of exploitation and measures of conservation.