scholarly journals Distribution and trend in abundance of the porbeagle (Lamna nasus) in the southern hemisphere

2013 ◽  
Vol 64 (6) ◽  
pp. 518 ◽  
Author(s):  
Yasuko Semba ◽  
Kotaro Yokawa ◽  
Hiroaki Matsunaga ◽  
Hiroshi Shono
Keyword(s):  
Southern Hemisphere ◽  
Longline Fishery ◽  
Effective Management ◽  
Catch Per Unit Effort ◽  
Limited Region ◽  
Cape Of Good Hope ◽  
Tasman Sea ◽  
The Indian Ocean ◽  
By Catch ◽  
Tuna Longline

Knowledge of a species’ distribution is an important element in its effective management and conservation. The porbeagle (Lamna nasus) is a common by-catch shark in the tuna longline fishery in the southern hemisphere, but its distribution and abundance are largely unknown. The investigation of observer data from the tuna longline fishery and other fishery survey data has revealed that (1) porbeagles are distributed in the pelagic waters across the oceans of the southern hemisphere, (2) juveniles and adults are distributed in cooler environments than are neonates, (3) pregnant females occur in the pelagic waters of the Indian Ocean and the Tasman Sea, most being frequently recorded around the Cape of Good Hope between June and July and (4) the standardised catch per unit effort (CPUE) based on tuna longline fishery (1994–2011) and driftnet survey (1982–1990) data indicate no continuous decreasing trend in the abundance of the southern porbeagle, contrary to the declining trend reported in a limited region in the South Atlantic. Considering its circumglobal distribution, stock status of this population should be assessed using information from the areas of its major distribution, including pelagic waters, and international coordination across oceans is necessary for the effective management of this population.

scholarly journals DISCARDS OF THE INDONESIAN TUNA LONGLINE FISHERY IN INDIAN OCEAN

2013 ◽  
Vol 19 (1) ◽  
pp. 25
Author(s):  
Bram Setyadji ◽  
Budi Nugraha
Keyword(s):  
Indian Ocean ◽  
Longline Fishery ◽  
Total Catch ◽  
The Indian Ocean ◽  
By Catch ◽  
Tuna Longline

Incidental by-catch and associated discarding are difficult to estimate on the basis of logbook information because they are poorly reported by fishing masters and their importance varies with several interrelated factors. The purpose of this paper is to inform the commonly discarded fishes of the Indonesian tuna longline fishery in the Indian Ocean. The study was carried out during 2010 – 2011 following six commercial tuna longline vessels based in Port of Benoa. Discards composition was dominated by longnose lancetfish and pelagic stingrays which composed almost half of total discards. Almost half of total catch are discards and half of discards are disposed dead or dying.

Pelagic shark bycatch in the New Zealand tuna longline fishery

2001 ◽  
Vol 52 (2) ◽  
pp. 165 ◽  
Author(s):  
Malcolm P. Francis ◽  
Lynda H. Griggs ◽  
Susan Jane Baird
Keyword(s):  
New Zealand ◽  
Pacific Ocean ◽  
Temporal Trends ◽  
Longline Fishery ◽  
Catch Per Unit Effort ◽  
Prionace Glauca ◽  
Isurus Oxyrinchus ◽  
Males And Females ◽  
North And South ◽  
Tuna Longline

Tuna longline effort declined from 23—26 million hooks per year in 1979mdash;82 to 2mdash;4 million hooks per year in 1995mdash;98. Scientific observer coverage averaged 7.5%since 1988mdash;89, but increased in 1992mdash;93 (mean 23%). Observed catch per unit effort (CPUE) and the numbers of hooks set were used to estimate shark catches. Between 1988mdash;89 and 1997mdash;98,about 450 000 blue sharks (Prionace glauca), 65 000 porbeagles (Lamna nasus ) and 25 000 shortfin makos (Isurus oxyrinchus) were caught. In 1997mdash;98,about 45 000 blue sharks, 4000 porbeagles and 3000 makos were caught. Corresponding weight estimates were 1400 t, 150 t and 200 t. CPUE varied between foreign and domestic vessels, between north and south regions and among years, but there were no consistent temporal trends. Most males and females were immature, and most sharks were alive when recovered. Most sharks were processed, but usually only the fins were retained. The New Zealand tuna longline fishery is probably not seriously affecting pelagic shark stocks, but adequate assessment is not currently feasible. Accurate monitoring of Pacific Ocean catches is an important first step towards ensuring sustainability of their populations.

Remarks on several icebergs which have been met with in unusually low latitudes in the southern hemisphere

1833 ◽  
Vol 2 ◽  
pp. 392-393
Keyword(s):  
Southern Hemisphere ◽  
East India Company ◽  
Rare Occurrence ◽  
Cape Of Good Hope ◽  
South West ◽  
Low Latitudes ◽  
The Indian Ocean ◽  
Sufficient Magnitude ◽  
The Antarctic ◽  
Northern And Southern Hemispheres

The journals of the ships belonging to the East India Company, the author observes, during the whole of the last century, contain no accounts of icebergs having been seen in the course of their navigation in the southern hemisphere, although several of these ships proceeded into the parallels of latitude 40°, 41°, and 42° south; but during the last two years, it appears that icebergs have occasionally been met with by several ships in their passage, very near the Cape of Good Hope, between the latitudes of 36° and 39°. The particulars relating to these observations are detailed in the paper. The most remarkable occurred in the voyage of the brig Eliza, from Antwerp, bound to Batavia, which on the 28th of April, 1828, fell in with five icebergs in latitude 37° 31' south, longitude 18° 17' east of Greenwich. They had the appearance of church steeples, of a height from 250 to 300 feet; and the sea broke so violently against these enormous masses, that it was at first suspected they might be fixed upon some unknown shoal, until, on sounding, no bottom could be discovered. It is remarkable that in general, icebergs appear to be met with in low latitudes, nearly at the same period of the year, namely, in April or May, in both the northern and southern hemispheres, although the seasons are reversed in these two divisions of the globe. In order to account for the origin and accretion of the southern icebergs, the author thinks it probable that there exists a large tract of land near the antarctic circle, somewhere between the meridian of London and the twentieth degree of east longitude; whence these icebergs have been carried in a north and north-north-easterly direction, by the united forces of current, winds, and waves, prevailing from south-south-west and south-west. Bouvet’s and Thompson’s Islands are not of sufficient magnitude, and Sandwich Land and Kerguelen’s Island are too remote to be the source of the icebergs lately observed in the vicinity of the Cape. From their unprecedented descent during the last two years, it is most probable that the disruption of these masses of ice from the place of their formation was the effect of some powerful cause of rare occurrence, such as an earthquake or volcano, which has burst forth and convulsed the inaccessible regions of the south; leaving no other testimonials of the event, than some few fragments of ice, scattered at a distance in the Indian Ocean.

scholarly journals JENIS DAN DISTRIBUSI UKURAN IKAN HASIL TANGKAP SAMPINGAN (BY CATCH) RAWAI TUNA YANG DIDARATKAN DI PELABUHAN BENOA BALI

2017 ◽  
Vol 5 (4) ◽  
pp. 453-460
Author(s):  
Skar Puji Astuti ◽  
Abdul Ghofar ◽  
Suradi Wijaya Saputra ◽  
Budi Nugraha
Keyword(s):  
Thunnus Albacares ◽  
Distribution Analysis ◽  
Target Species ◽  
Catch Per Unit Effort ◽  
Prionace Glauca ◽  
Thunnus Obesus ◽  
Southern Bluefin Tuna ◽  
By Catch ◽  
Research Show ◽  
Tuna Longline

ABSTRAK Hasil tangkapan rawai tuna terdiri dari dua jenis yaitu hasil tangkapan utama (target species) dan hasil tangkapan sampingan (by catch). Penelitian ini bertujuan untuk mendapatkan informasi jenis ikan hasil tangkapan utama dan ikan hasil tangkapan sampingan rawai tuna, menghitung komposisi ikan, menganalisa distribusi ukuran ikan dan mengetahui nilai CPUE ikan HTU dan ikan HTS. Penelitian dilaksanakan pada bulan April-Mei 2016 dengan mengikuti kegiatan sampling enumerator Loka Penelitian Perikanan Tuna Benoa, Bali. Hasil penelitian menunjukkan jenis ikan hasil tangkapan utama rawai tuna yaitu ikan Tuna mata besar (Thunnus obesus), Tuna sirip kuning (Thunnus albacares), Tuna sirip biru selatan (Thunnus maccoyii) dan Tuna albakora (Thunnus allalunga). Jenis ikan hasil tangkapan sampingan rawai tuna yang mendominasi yaitu ikan opah (Lampris guttatus), hiu air (Prionace glauca) dan escolar (Lepidocybium flavobrunneum). Perbandingan komposisi ikan hasil tangkapan utama yaitu 69% dan ikan by catch 31%. Distribusi ukuran ikan hasil tangkapan sampingan sebagian besar sudah memenuhi kriteria ikan layak tangkap. CPUE ikan hasil tangkapan sampingan lebih rendah dibandingkan dengan ikan hasil tangkapan utama. Kata kunci: Hasil Tangkapan Sampingan (by catch), Rawai Tuna, Pelabuhan Benoa Bali, Samudera Hndia.  ABSTRACT Catch of Tuna longline has two types, that is target species and by catch product. This research aims to determine the information type of target species and species by catch, calculate the composition of the fish, size of distribution analysis and determine the CPUE (Catch per unit effort) of species by catch and target species. This research is conducted in April-May 2016 following the sampling enumerator activities of Benoa port. The results of the research show that the type of target species Tuna Longline there are Big eye tuna (Thunnus obesus), Yellow fin tuna (Thunnus albacares), Southern bluefin tuna (Thunnus maccoyii) and Albakora (Thunnus allalunga). The types of species by catch Tuna Longline dominates that is Opah (Lampris guttatus), Shark (Prionace glauca) and Escolar (Lepidocybium flavobrunneum). Comparison of the composition target species is 69% and species by catch is  31%. The size distribution of species by catch already most the criteria of decent fish caught. CPUE of species by catch was lower than. Keywords: bycatch, tuna longline, benoa port, indian Ocean

scholarly journals The shark by-catch of tuna longline fisheries in Southern Indian Ocean of Java, Indonesia

2018 ◽  
Vol 74 ◽  
pp. 02004
Author(s):  
Priyo Suharsono Sulaiman ◽  
Mufti Petala Patria ◽  
Rauf Achmad Sue
Keyword(s):  
Indian Ocean ◽  
Time Series Data ◽  
Southern Indian Ocean ◽  
Fishing Ground ◽  
Series Data ◽  
The Indian Ocean ◽  
By Catch ◽  
Catch Composition ◽  
Longline Fisheries ◽  
Tuna Longline

In relation to the achievement of the target SDG’s No. 14, the sustainable shark fisheries management need to implement. As a part of the tuna fisheries by-catch, a high number of shark resources have been caught in the Indian Ocean waters. One of the main vessels of tuna catchers in the Southern Indian Ocean of Java is the tuna longline from Cilacap. This paper aims to analyze the shark by-catch of tuna longline in the Indian Ocean in the south Java that landed in Cilacap. The research data was obtained from daily recording activities of fishing vessel loading activities by Cilacap Ocean Fisheries Port staff during the period of 2013-2017. The analysis was done through data tabulation, graphical approaches, and data trend analysis through the availability of time series data. The data analyzed include fleet development, fishing ground, catch composition and CPUE value. The results of the analysis show that there are about eight species of sharks that are by-catch of tuna longline from Cilacap. The highest shark by-catch occurred in April with CPUE averaging 9 kg/day/vessel. The blue shark (Prionace glauca) is the dominant shark catch which reaches 66% of the total sharks catch.

Killer whale (Orcinus orca) interactions with the tuna and swordfish longline fishery off southern and south-eastern Brazil: a comparison with shark interactions

2007 ◽  
Vol 87 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Luciano Dalla Rosa ◽  
Eduardo R. Secchi
Keyword(s):  
Killer Whale ◽  
Longline Fishery ◽  
Catch Per Unit Effort ◽  
Killer Whales ◽  
Additional Information ◽  
South Eastern ◽  
Eastern Brazil ◽  
Negative Impacts ◽  
By Catch ◽  
Longline Fisheries

Depredation by cetaceans and sharks on longline fisheries is a global issue that can have negative impacts on both animals and fisheries and has concerned researchers, managers and the fishing industry. Nevertheless, detailed information on depredation is only available for a few regions where the problem exists. With the purpose of evaluating killer whale depredation on longline-caught tuna (Thunnus spp.) and swordfish (Xiphias gladius) in the waters off southern and south-eastern Brazil and comparing it to shark depredation, data sheets were distributed to the captains of tuna vessels in Santos, south-eastern Brazil, between 1993 and 1995. Data on the catch per unit effort (CPUE) of tuna and swordfish and some records of interactions were also obtained from fishing vessel logbooks. Dockside interviews with fishermen and with researchers on board tuna vessels provided additional information. Killer whale and shark interactions were analysed per longline set and per trip. Killer whale interactions occurred from June to February, mainly between June and October, while shark interactions occurred year round. The number of sets and trips involving shark interactions was significantly higher than the number of sets and trips involving killer whale interactions. However, when depredation occurred, the proportion of fish damaged by killer whales was significantly higher than by sharks. Furthermore, killer whales removed or damaged significantly more hooked swordfish than hooked tuna, whereas sharks damaged significantly more hooked tuna than swordfish. This study also shows that cetacean by-catch is experienced by the tuna and swordfish longline fishery in Brazilian waters.

Are circle hooks effective management measures in the pelagic longline fishery for sharks in the Gulf of Gabès?

2020 ◽  
Vol 30 (6) ◽  
pp. 1172-1181
Author(s):  
Bechir Saidi ◽  
Khaled Echwikhi ◽  
Samira Enajjar ◽  
Sami Karaa ◽  
Imed Jribi ◽  
...  
Keyword(s):  
Longline Fishery ◽  
Effective Management ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Management Measures ◽  
Pelagic Longline Fishery ◽  
Pelagic Longline

Fish and invertebrate by-catch in the crab pot fishery in the Isle of Man, Irish Sea

2017 ◽  
Vol 98 (8) ◽  
pp. 2099-2111
Author(s):  
Fikret Öndes ◽  
Michel J. Kaiser ◽  
Lee G. Murray
Keyword(s):  
Irish Sea ◽  
Target Species ◽  
Catch Per Unit Effort ◽  
Isle Of Man ◽  
Ecosystem Effects ◽  
By Catch ◽  
Catch Rates ◽  
Taxonomic Groups ◽  
Catch Composition ◽  
Autumn And Winter

Baited trap or pot fisheries are considered to have relatively few wider ecosystem effects on the marine environment, particularly when compared with towed mobile fishing gear. However, this assumption is rarely tested in the field. This study aimed to determine the composition of non-target species that occur in crustacean pots and to assess spatial and temporal differences in catches in the waters around the Isle of Man, Irish Sea. The data were collected using fishery independent surveys and a questionnaire study. Based on fishery independent surveys, a total of five taxonomic groups and 43 species occurred as by-catch. The dominant by-catch species was velvet crab Necora puber. The by-catch per unit effort (BPUE) for all of the non-target species was low particularly in comparison to towed bottom gear fisheries around the Isle of Man. BPUE of species composition varied considerably between different locations around the Isle of Man. The results of both the fishery independent and questionnaire data suggested that the by-catch rates varied with season with peak BPUE occurring in spring which then declined into autumn and winter. By-catch composition did not decrease significantly with an increasing target species catch. Overall, by-catch was low relative to target species catch which may be partially attributable to the use of escape panels in pot fisheries in the Isle of Man.

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