scholarly journals Historical Ecology of the San Diego Sport Fishery: Catch Composition, Species Trends, and Fishing Effort from 1959 to 2011

2021 ◽  
Author(s):  
◽  
Rebecca Schwartz
2010 ◽  
Vol 20 (8) ◽  
pp. 2203-2222 ◽  
Author(s):  
P. Ed Parnell ◽  
Paul K. Dayton ◽  
Rachelle A. Fisher ◽  
Cina C. Loarie ◽  
Ryan D. Darrow

2021 ◽  
Vol 8 ◽  
Author(s):  
Chih-Shin Chen

Precious corals are a fishery resource of cultural and religious importance. Because of their high commercial value, precious corals have been exploited for several centuries in the Mediterranean and for almost one century in the Northwest Pacific. Taiwanese fishing fleets have harvested precious corals since the 1920s; however, management regulations have only been promulgated since January 2009, when the catch and effort data of fisheries began to be collected. This study examined spatiotemporal variation in the catch composition and abundance of precious corals Corallium, Hemicorallium, and Pleurocorallium spp. around Taiwan using fishery data from 2009 to 2018 and discussed its implications for fisheries management. Licenses are issued for 60 vessels annually, and the annual total catch was 2.9–3.5 t between 2009 and 2018, peaking in 2015 and then decreasing sharply in 2016. Because of the use of non-selective fishing gear, dead and fossilized colonies were included in the total catches of the fishery. Fossilized colonies were predominant (average 78.5%) in the total catches, whereas the proportion of live colony catches accounted for less than 5%. Pink coral (Momo) was predominant in the total and live colony catches during the 10-year period. The Taiwanese precious coral fishing fleets are restricted to harvesting precious corals in five designated fishing grounds (DFGs; A–E). The fishing effort (vessel⋅day) was mainly concentrated in DFG-A (average 56.6%), which accounted for an average of 63.9% of the total catches. However, the live colony catches were largest in DFG-E (average 39.9%) and DFG-A (average 39.6%). The annual catch rates of live colonies decreased in two major fishing grounds (DFGs-A and DFG-B), whereas it increased in two minor fishing grounds (DFGs-C and DFG-D). The temporal variation in occurrence rates of live colonies decreased between 2015 and 2018, indicating a declining trend for precious coral populations around Taiwan. These results indicate that an unsustainable condition may occur in the near future if the precious corals continue to be harvested at the current scale. Revised regulations for the Taiwanese precious coral fishery should contain proposals on fishing gear modifications, a rotational harvesting scheme, or both; such measures can contribute to the conservation of precious coral populations. Regional cooperation in fisheries management is necessary to achieve the sustainable development of precious corals and their fisheries in the Northwest Pacific.


2021 ◽  
Vol 38 (2) ◽  
pp. 181-188
Author(s):  
Ozan Soykan ◽  
Cemil Sağlam ◽  
İlker Aydın ◽  
Hasan Tuncay Kınacıgil

This study aimed to determine the impact of hook and bait type on the catch composition and catch per unit effort. Effects of hook and bait types on catch composition, catch per unit effort (CPUE), length and weight distributions in demersal longline fishery were determined by experimental surveys on demersal longline sets in the Aegean Sea. A total of 12 samplings corresponding to 4800 hook fishing effort were performed between April 2014 and September 2014. Two bait types; sardine (Sardina pilchardus) and grooved razor shell (Solen marginatus) and two hook types; J-hook and C-hook were tested. CPUE values were calculated for each species and assessed between different hook-bait combinations. A total of 623 individuals were captured belonging to 3 families and 9 species. It was found that more than 60% of total catch was captured by grooved razor shell and more than 50% of the total catch was caught with J type hook. J hook was found to be close to significant (p=0.06) and grooved razor shell was found significant (p=0.02) for CPUE. The effect of bait type was found to be more significant than that of hook type for CPUE and length distribution. Hook-bait combination differed according to species and C hook baited with sardine was determined to be the best combination for Sparus aurata as the most targeted fish in the study area. Discard ratio was calculated to be 34% in terms of weight and 42.5% in terms of total number of individuals for pooled data. The condition value (K) of the species ranged from 1.05 to 1.68 and differed according to bait type. Most of the high commercial value species caught with any hook-bait combination experimented within this study are larger than minimum fishing length according to minimum landing size regulations of Turkish fishery and maturity studies.


1990 ◽  
Vol 41 (1) ◽  
pp. 175 ◽  
Author(s):  
JP Glaister ◽  
SS Montgomery ◽  
VC McDonall

The eastern king prawn, P. plebejus, has been commercially exploited for over 50 years. Controversy has arisen over the presumed effect of increasing fishing effort on reported declining catch per vessel and the need for further management of the fishery. The present study develops the information necessary to evaluate this presumption by analysing landing statistics, data developed from a log-book programme, commercial catch composition and data from a series of mark-recapture experiments conducted on part of the fishing grounds. Population parameters (growth, mortalities and other losses) were calculated via a series of tagging experiments. Recapture rates of tagged prawns were examined for each point release (local recapture) and for the state as a whole (sequentially applied effort), the difference providing estimates of emigration rate. Weekly values chosen for these parameters allowed calculation of yield-per-recruit estimates. For 1979 and 1980, respectively, fishing mortality estimates ranged between 0.04 and 0.08 per week, depending upon number of vessels per port; emigration was estimated to be 0.13 and 0.18 per week for the two years, tagging mortality (0.08 per week), and all other losses other than by tagging and emigration at 0.06 and 0.08 per week. A compartmented, time-lagged model of the fishery was used to predict changes in yield per recruit as a consequence of changes in management strategy and to describe the relationship between fishing effort and yield per recruit. The analyses suggested that limited benefits in terms of yield per recruit would eventuate from substantial increases in effort but that substantial decreases in catch per effort were likely.


2020 ◽  
Vol 48 (4) ◽  
pp. 637-648
Author(s):  
Jorge A. López-Rocha ◽  
Laura Vidal-Hernández ◽  
Arturo Bravo-Calderón

Sportfishing is an activity of increasing popularity that involves a large number of users and high levels of fishing effort. In Yucatan, most of the target species in sport fishing are the same as those of commercial fisheries. However, there is no record of fishing effort or catch volumes. Thus the impact of sport fishing on these populations is unknown. This study analyzes the catches made by users of sport fisheries of nine species (Epinephelus morio, Haemulon plumieri, Seriola dumerili, Lutjanus synagris, Ocyurus chrysurus, Calamus bajonado, Sphyraena barracuda, S. guachancho and Mycteroperca bonaci) through length-based indicators. Samples of species’ sizes were obtained from the catches made during 10 fishing tournaments held in Yucatan's three-port towns (Sisal, Yucalpeten, and Telchac) between 2015 and 2016. The catch variables that were evaluated included: the number of mature individuals Pmat, optimal length Popt, and the number of mega-spawners Pmega. Length measures were derived from 1,252 individuals. Only H. plumieri, L. synagris, and S. guachancho exhibited sustainable indicator values, while E. morio and C. bajonado demonstrated extremely low values. In most species, sport fishing affects a high proportion of juveniles. The results suggest that sportfishing contributes to the fishing pressure of a species and commercial fishing, due to the capture of juveniles of economically important fish. It is essential to establish a systematic monitoring method of such activities and increase the priority level of the evaluation and management of this fishery.


2003 ◽  
Vol 54 (4) ◽  
pp. 425 ◽  
Author(s):  
Michael Lowry ◽  
Jeff Murphy

The east coast Australian gamefish fishery is a diverse, multi-species fishery that targets billfish, sharks, tuna and other pelagic fish along the east Australian seaboard. A Gamefish Tournament Monitoring Program (GTMP) was undertaken, and 39021 angler trips from 1996 to 2000 were analysed. The program reports on trends in fishing effort, catch rates, catch composition, proportions of captures tagged and released and spatial distribution of catches for the principal recreational billfish species: black marlin (Makaira indica), striped marlin (Tetrapterus audax) and blue marlin (Makiara nigricans).The GTMP was principally designed as part of an integrated program to monitor the recreational gamefish fishery. The spatial and temporal design of the program restricted statistical analyses however, there were trends in fishing effort, directed effort, catch rates, catch composition, proportions of fish tagged and spatial distribution of catches for the principal recreational billfish species over seven successive years (1994–2000). Analysis of catch data, stratified by directed effort, indicated significant differences in catches of target species, demonstrating the importance of calculating catch rate estimates according to the main target preference. Analysis of tournament based tagging information indicated that while overall tournament tagging rates remained high (88%) there were significant differences in the number of fish tagged between species groups highlighting the impact that angler attitude and the competition point score structure has on the harvest of gamefish target species.


Author(s):  
Rani Ekawaty ◽  
. Musyafak ◽  
Irwan Jatmiko

<p>ABSTRACT<br /><br />The utilization of fishery resources in the Indian Ocean, especially in the southwest of Sumatra Island, south of Java, Bali to Nusa Tenggara is expected to increase. The objective of this study was to determine the composition of the catches and the catch rate of hand line based on PPI Oeba, Kupang. Research conducted at the Fish Landing (PPI) in Oeba, Kupang, Nusa Tenggara Timur from January to March 2015. The method used is descriptive method in which the research is intended to describe the phenomenon that occurred in the handline fishery and its catch. Catch data and fishing effort are analyzed to determine the value of the catch per unit of fishing effort. To determine differences in fishing fleet catches large and small pull-t test. About 60% catch of handline GT&lt;10 dominated by tuna (Thunnus sp) and skipjack (Katsuwonus pelamis). While the GT&gt;10 dominated by snapper (Lutjanus sp), anggoli (Pristipomoides multidens) and grouper (Epinephelus sp) with percentage of more than 70% of the total catch. There was a significant difference to the average catches between fleets with GT&lt;10 and GT&gt;10 (t = -9.538; df = 2404, p &lt;0.001). The average catch of fishing fleet GT&gt; 10 was 1,074 kg, or about twice that of the average catches of fishing fleets with GT &lt;10 only amounted to 539 Kg. This information can be used as input in the management and development of hand line fishing in the PPI Oeba, Kupang.<br /><br />Keywords: catch composition, catch rate, fishing effort, t-test</p><p>------<br /><br />ABSTRAK<br /><br />Pemanfaatan sumberdaya ikan di Samudera Hindia terutama di sebelah barat daya Pulau Sumatera, selatan Pulau Jawa, Pulau Bali sampai Nusa Tenggara cenderung meningkat. Penelitian ini bertujuan untuk mengetahui komposisi hasil tangkapan dan laju tangkap pancing ulur yang berbasis di Pangkalan Pendaratan Ikan (PPI) Oeba, Kupang.Penelitian dilakukan di PPI Oeba, Kota Kupang, Nusa Tenggara Timur dari bulan Januari – Maret 2015. Metode yang digunakan adalah metode deskriptif dimana penelitian ini ditujukan untuk menggambarkan fenomena yang terjadi pada perikanan pancing ulur dan hasil tangkapannya.Data hasil tangkapan dan upaya penangkapan yang dianalisis untuk menentukan nilai hasil tangkapan per satuan upaya penangkapan.Untuk mengetahui perbedaan hasil tangkapan armada pancing ulur besar dan kecil dilakukan uji-t.Sekitar 60% hasil tangkapan armada pancing ulur dengan GT&lt;10 didominasi oleh tuna (Thunnus sp) dan cakalang (Katsuwonus pelamis). Adapun hasil tangkapan armada pancing ulur dengan GT&gt;10 didominasi oleh kakap (Lutjanussp), anggoli (Pristipomoides multidens) dan kerapu (Epinephelus sp) dengan persentase ketiganya sebesar lebih dari 70%.Terdapat perbedaan yang nyata terhadap rata-rata hasil tangkapan antara armada GT&lt;10 dengan GT&gt;10 (t=-9,538; df=2404; p&lt;0,001). Rata-rata hasil tangkapan armada pancing ulur dengan GT&gt;10 sebesar 1.074 kg atau sekitar dua kali lipat dibandingkan rata-rata hasil tangkapan armada pancing ulur dengan GT&lt;10 yang hanya sebesar 539 kg. Diharapkan informasi ini dapat dijadikan masukan dalam pengelolaan dan pengembangan perikanan pancing ulur di PPI Oeba, Kupang.<br /><br />Kata kunci: komposisi hasil tangkapan, laju tangkap, upaya penangkapan, uji-t</p>


2020 ◽  
Vol 19 (1) ◽  
pp. 45-53
Author(s):  
Mumini Dzoga ◽  
Danny Simatele ◽  
Cosmas Munga

Shore-based assessment of fisheries resources in Ngomeni, Kipini and Ozi fishing areas of Malindi-Ungwana Bay and the Lower Tana Delta on the north coast of Kenya was conducted from January to December 2017 to establish catch composition, species richness, and fishing effort (catch-rate, number and types of fishing gears and crafts) in the marine, estuarine and riverine habitats. Distinct catch composition (R = 0.27, P < 0.05) was observed across the three habitats. Catch composition differed significantly spatially and seasonally across the three fishing areas, and between the north east (NE) and south east (SE) monsoon seasons (R = 0.332, P < 0.05). The wolf herring, Chirocentrus dorab, was the most abundant fish species in Ngomeni, centrally located in Malindi-Ungwana Bay, while the catfishes, Arius africanus and Clarias gariepinus, were the most abundant species in Kipini and Ozi, respectively. Gillnets operated from dhows (mashua) and fibre-reinforced plastic (FRP) boats in Ngomeni (marine), and canoes using-basket traps in Ozi (riverine), landed significantly larger Spanish mackerel, Scomberomorus commerson, and sea catfish, Arius africanus (Kruskal Wallis test: Df = 2; F = 197.141; p < 0.001; Df = 2, F = 490, p < 0.001), respectively. Species diversity by area in combination with habitat and type of fishing craft showed higher diversity for Ngomeni in the marine habitat with mashua fishing crafts than in Kipini. Significantly different catch rates (Df = 2, F = 10.43, p<0.001; Df = 1, F = 5.897, p < 0.021) were observed in the three (3) fishing areas and during the NE monsoon and the SE monsoon, respectively. Canoes were the most common fishing craft used, especially in Ngomeni, accounting for 37.1%, and 97.5% in Ozi, while mashua crafts accounted for 44.5% of the total fishing craft in Kipini. Monofilament nets were most common in Ngomeni (34.0%) while basket traps dominated the Ozi site at 63.6%. The Kipini area was dominated by handlines (28.8%). It is therefore evident that the three (3) fishing areas of the Malindi-Ungwana Bay and Lower Tana Delta showed significant differences in catch composition and size of fish caught, attributed partly to the variation in habitat types and fishing methods between the sites. Overall, the Ngomeni area was characterized by more advanced fishing craft with the majority powered by engines, including mashua and FRP boats, compared to Kipini and Ozi fishing areas where canoes were dominant.


2010 ◽  
Vol 47 (2) ◽  
pp. 188-200 ◽  
Author(s):  
Gustavo Hallwass ◽  
Priscila Fabiana Lopes ◽  
Anastacio Afonso Juras ◽  
Renato Azevedo Matias Silvano

1988 ◽  
Vol 45 (10) ◽  
pp. 1771-1778 ◽  
Author(s):  
Lyse Godbout ◽  
Robert H. Peters

Evaluation of four existing empirical models of fish yield showed their applicability to be limited for the brook trout (Salvelinus fontinalis) sport fishery in the Laurentian shield because these models explained < 60% of the variation in catch. In at least 80% of the lakes, observed catch exceeded that predicted by two of the models. The other models overestimate catch by 100% or more in at least 25% of the lakes. As a first step to improve these models, we identify correlates of "stable catch," defined by the absence of a significant temporal trend in fishing success in lakes for which at least five consecutive years of data were available. Data available or calculable from government sources and maps were used to construct models that identified fish size, lake trophy, altitude, and pH as promising correlates. A second series of models based on our own field determinations confirmed these findings. After fishing effort had been taken into account, these variables reduced the unexplained variation by up to 50%. Although our estimates of trophy and acidity were crude, this study suggests that these indicators should be included in future models to describe and predict the yield of sport fisheries.


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