Associations between sea temperature, catch per unit of fishing effort, and yield in the Bermuda spiny lobster fishery, 1975-1989

1995 ◽  
Vol 46 (5) ◽  
pp. 809 ◽  
Author(s):  
CR Evans ◽  
APM Lockwood ◽  
AJ Evans

Results of graphical analyses of annual records of catch, effort and sea temperature indicate empirical quadratic associations between industry catch per unit of fishing effort (CPUE) in Bermudan spiny lobster (Panulirus argus and P. guttatus) fisheries and the annual average sea temperature at Hamilton Harbour, Bermuda. CPUE and yield of P. argus and of P. guttatus were each associated by quadratic expressions with the annual average sea temperature of the Bermuda Platform. Annual growth and survival of late juvenile P. argus and P. guttatus into the fishable stock at Bermuda is controlled in a quadratic fashion chiefly by sea temperature with a six-month lag. The optimum annual average sea temperature for the survival and growth of late benthic juvenile P. argus into the fishery stock was 23.6 � 0.2�C (mean � s.e.), and the comparable optimum for P. guttatus juvenile recruitment was 24.1 � 0.1�C. The maximum equilibrium catch of P. guttatus lobsters on Bermuda Platform was estimated at approximately 33 000 lobsters from quadratic regression of yield on fishing effort.

2007 ◽  
Vol 58 (2) ◽  
pp. 166 ◽  
Author(s):  
D. M. Parsons ◽  
D. B. Eggleston

Animals that interact with but are not retained by fishing gears may later die. The population and economic consequences of these sublethal fishery interactions are seldom known but may be significant. In the present study, a population model was used to quantify potential population and economic consequences of injuries that Caribbean spiny lobsters (Panulirus argus) sustain from fishing activities in the Florida Keys, USA. Injuries generated by the fishery are known to reduce growth and elevate mortality. Simulation modelling results indicated that injuries may reduce adult lobster abundance and associated landings by ≥50% in areas with high recreational fishing effort. When simulated injuries were ~20 times lower (representing areas with lower fishing effort), these injuries were only responsible for a 5 and 8% reduction in the adult lobster population and commercial landings respectively. Important parameters within the model (growth, time in stage and mortality of injured lobsters) were altered by ±10% to assess model sensitivity. Final results changed <10% (with the exception of one 15% change), suggesting that model output was relatively insensitive to variation in key parameters. When the impact of sublethal injuries was applied to the entire spiny lobster fishery in the Florida Keys, adult stock biomass and annual commercial landings were reduced by 900 and 160 t (US$1.6 million) respectively. These results suggest that sublethal fishery interactions can lead to high population and economic losses, and highlight the need to incorporate sublethal injuries into stock assessments and economic models.


2001 ◽  
Vol 52 (8) ◽  
pp. 1623 ◽  
Author(s):  
K. L. Cochrane ◽  
K. L. Cochrane ◽  
B. Chakalall ◽  
B. Chakalall

The Caribbean spiny lobster Panulirus argus is widely distributed in the western central Atlantic and supports important fisheries in many of the countries within this area. Total reported landings have been between 27000 and 30000 tonnes per annum over the last decade. However, recent assessments undertaken under the auspices of the Western Central Atlantic Fisheries Commission (WECAFC) have indicated that the resource is being fully or over-exploited over much of its range. The results also revealed widespread deficiencies in the data available, which create problems in undertaking reliable assessments and in the subsequent provision of management advice. The studies, undertaken with full regional participation, suggested that in most countries the need is urgent to control and frequently to reduce fishing effort for the species and that in some countries both spawner biomass and potential yield would benefit from increases in the minimum size of the lobsters caught. This paper describes the fisheries for Caribbean spiny lobster, including their socio-economic importance in the region. It provides an over-view of the results of the 1997 and 1998 WECAFC workshops on the species and of the implications of those results for management for sustainable use. Finally, the need for regional, or, at least, subregional, management of the fisheries is discussed, with reference to the conclusions of the WECAFC 2000 workshop.


1991 ◽  
Vol 48 (11) ◽  
pp. 2073-2082 ◽  
Author(s):  
A. Campbell ◽  
D. J. Noakes ◽  
R. W. Elner

Commercial landings of American lobster (Homarus americanus) have increased dramatically in many areas along the east coast of Canada since the late 1970's. Average annual sea surface temperatures (SST) were analysed to test if lobster landings were related to changes in the marine environment. Time series models were fitted to lobster landings and SST data from Maine (USA), Halifax County (Nova Scotia), and Charlotte County (New Brunswick). Including temperature in the models improved forecasting ability for lobster catches for Maine and Halifax but not Charlotte. In Maine, lobster landings in year t were related to SST in year t. In Halifax, however, landings were related to SST in the previous 4 yr but not by SST of the current year. Lower fishing effort levels for Halifax compared with Maine probably extended the yield from strong year-classes through a number of years. We surmise that an increase in sea temperature near Halifax during the early 1980's increased the survival and growth rates of lobster juveniles. This provided a strong pulse of recruits to the fishery throughout coastal Nova Scotia during the mid- to late 1980's. Similar increases in temperature and landings were not observed for Maine and Charlotte.


2001 ◽  
Vol 52 (8) ◽  
pp. 1459 ◽  
Author(s):  
Graeme A. Moss ◽  
Lennard J. Tong ◽  
Sarah E. Allen

Instar 1, 3, 5, and 7 phyllosomas of the spiny lobsterJasus verreauxi were reared individually at one of four temperatures (18, 21, 24, and 27C) and fed low, medium, or high rations of 2- to 3-mm Artemia salina. An increase in the temperature reduced the intermoult period for all instars tested, but only the instar 5 phyllosomas showed any significant differences in postmoult size with temperature; those at 18C were smaller. Phyllosomas reared at 18C ate fewer Artemia each day than did those at the higher temperatures, but instars 3 and 5 at 18C consumed more in total over the intermoult period. Survival for all instars tested was lowest at 18C. Increasing the food rations affected the growth and survival of instar 5 and 7 phyllosomas; those fed at the lower rations took longer to moult and had a smaller growth increment. For all instars tested, the feeding rate and total consumption increased with food ration.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7278 ◽  
Author(s):  
Juan Carlos Murillo-Posada ◽  
Silvia Salas ◽  
Iván Velázquez-Abunader

Management of low-mobility or benthic fisheries is a difficult task because variation in the spatial distribution and population dynamics of the resources make the monitoring and assessment of these fisheries challenging. We assumed that environmental, spatial, and temporal factors can contribute to the variability of the relative abundance of such species; we used Generalized Additive Models for Location Scale and Shape (GAMLSS) to test this hypothesis using as a case study the lobster fishery (targeting two species) in the Galapagos Marine Reserve, Ecuador. We gathered data on each of the two species of lobster on a monthly basis over seven years, including: (a) onboard observers’ records of catch data, fishing effort, and ground location by trip, and (b) data from interviews undertaken with fishers at their arrival to port, recording the same type of information as obtained from onboard observers. We use this information to analyze the effect of the measured variables and to standardize the Catch per Unit Effort (CPUE) in each case, using the GAMLSS. For both species, the temperature, region, fishing schedule, month, distance, and the monitoring system were significant variables of the selected models associated with the variability of the catch rate. ForPanulirus penicillatus, CPUE was higher at night than during the day, and forPanulirus gracilisit was higher during the day. Increased temperature resulted in a decrease of CPUE values. It was evident that temporal, spatial scales and monitoring system can influence the variability of this indicator. We contend that the identification of drivers of change of relative abundance in low-mobility species can help to support the development of monitoring and assessment programs for this type of fisheries.


Author(s):  
Abraham Demekristos

The aims of the study were to evaluate seedling growth and survival of Prunus africana provenances in awi highland based on ecological requirement of the tree. We measured survival and growth of three P.africana provenances seedlings found in Ethiopia (provenances sources namely: Gedeo, Jibat and Munnessa). Design of experiment with randomized complete block design (RCBD) with three replications. Seedlings planted at 2m, 2.5m and 3m distance between plants, plot, and blocks respectively. A plot size of 10mx10m and 25 plants are found per plot (0.01ha). We used ANOVA to test differences in survival, and growth among provenances over time. Results concluded that, provenances have no significant variation among in establishment rate, plant height and collar diameter growth. Of these provenances, Jibat was the first in establishment (56%), second in height (1.97m) and diameter (2.89cm). Gedeo was stood first in height (2.30m) but second in establishment rate (52%) and thickness(3.45cm), but Munessa with very good growth in diameter(3.59cm) might be prefreed for bark extraction followed by Gedeo, last in height (1.75m),but established second (52%). Contrary to expectations, seedlings were still at substantial risk of mortality &ge;3 years after planting. Probably the plants survival rate and growth probably affected by altitude, soil water potential, light exposure, and wild animal presence in the surrounding. In steep slope sites, canopy shade, existing weed vegetation as well as wild animals such as apes is unlikely to enhance seedling survival after planting. Our results suggest that seedling mean growth increased with 0.008mm thickness and 0.41mm per day while 2.8mm thickness and 146.8mm tall increment recorded in 2560meter elevated high land or injibara with mean value of 18.5&deg;C and rain fall is 1300mm.


2018 ◽  
Vol 23 (3) ◽  
pp. 215 ◽  
Author(s):  
Zairion Zairion ◽  
Nefi Islamiati ◽  
Yusli Wardiatno ◽  
Ali Mashar ◽  
Rudi Alek Wahyudin ◽  
...  

Dinamika populasi merupakan aspek penting sebagai dasar pengelolaan perikanan dan informasi tentang aspek tersebut pada lobster pasir masih minim di perairan Palabuhanratu. Tujuan penelitian ini adalah mengkaji aspek pertumbuhan, pola rekrutmen, mortalitas dan laju eksploitasi lobster pasir (Panulirus homarus) di perairan Palabuhanratu. Penelitian ini dilakukan periode Juni 2015-Mei 2016 dengan metode sensus. Lobster pasir hasil tangkapan jaring insang dasar dengan jumlah total sampel 483 ekor mempunyai panjang karapas antara 28-100 mm. Pola pertumbuhan berdasarkan hasil regresi linear memperlihatkan allometrik negatif. Hasil analisis menggunakan metode ELEFAN I (Electronic Length Frequency Analysis) menunjukan koefisien pertumbuhan lobster pasir jantan (K = 0,29 per tahun), lebih kecil dibandingkan dengan betina (K = 0,40 per tahun). Rekrutmen terindikasi dua puncak dalam setahun: yaitu pada Februari-Mei dan September-Oktober). Laju mortalitaskarena penangkapan (F) mencapai 1,9-2,2 kali laju mortalitas alami (M). Nilai Lc<Lrmemperlihatkan lobster pasir sudah tertangkap sebelum mencapaiukuran rata-rata mengerami telur atau ukuran kematangan reproduktif. Laju eksploitasi lobster pasir mencapai 32-38% di atas laju eksploitasi optimum, sehingga lobster pasir sudah mengalamieksploitasi yang berlebih.Population dynamics is an important aspect as basic of fisheries management and little information of this aspect for spiny lobster fishery in Pelabuhanratu waters. This research aims to evaluate of growth aspects, recruitment pattern, mortality, and exploitation rate of scalloped spiny lobster (Panulirus homarus) in Palabuhanratu waters. This research was conducted in June 2015 until May 2016 using census method. The size of P. homarus captured using bottom gill-net with total sample 483 specimen was between 28-100 mm carapace lengths (CL). Linear regression showed that growth pattern was negative allometric. The growth coefficient of male (K = 0.29 per year) was found smaller than female (K = 0.40 per year) based on ELEFAN I (Electronic Length Frequency Analysis) method. Recruitment seems to be accrued twice peaks a year (February to May and September to October) and the highest was at February to May. Fishing mortality (F) reached 1.9 to 2.2 times of natural mortality (M). The LcÂLr value showed that female has been caught before reached the average size of bearing eggs or reproductive maturity size. The exploitation rate of spiny lobsters reaches 32-38% above optimum level. This study suggests that the spiny lobster fishery in Palabuhanratu in the state of overexploitation.


2015 ◽  
Vol 7 (3) ◽  
pp. 121
Author(s):  
Duranta D Kembaren ◽  
Erfind Nurdin

Penelitian tentang distribusi ukuran dan parameter populasi lobster pasir di perairan Aceh Barat dilakukan pada bulanApril sampai November 2013. Penelitian ini bertujuan untukmengkaji status lobster di perairan Aceh Barat dilihat dari aspek distribusi ukuran dan parameter populasinya. Pengamatan dan pengukuran lobster dilakukan di tempat pengumpul lobster dengan sistem sampling acak. Sebaran frekuensi panjang karapas selanjutnya ditabulasikan dan dianalisa dengan metode kurva logistik. Struktur ukuran lobster yang tertangkap menunjukkan bahwa lobster jantan dominan tertangkap dibawah ukuran nilai tengah 72,5 mm dan sebaliknya diatas ukuran nilai tengah 72,5 mm yang didominasi jenis kelamin betina. Lobster terlebih dahulu tertangkap sebelum mencapai ukuran matang gonad (Lc = 65,8mm< Lm= 76,8 mm). Puncak musim pemijahan terjadi pada bulan Mei dan Agustus. Panjang asimtosis (CL∞ ) sebesar 119,5 mm dengan laju pertumbuhan (K) 0,39/tahun serta laju kematian total (Z) 1,44/tahun, laju kematian alamiah (M) 0,67/tahun dan laju keamatian akibat penangkapan (F) 0,77/tahun. Laju eksploitasi sudah mengarah kepada penangkapan yang berlebih (E=0,54), oleh karena itu perlu dilakukan tindakan pengelolaan perikanan lobster yang berkelanjutan. Salah satu upaya yang dapat di tempuh adalah dengan menerapkan sistem penutupan musim penangkapan lobster pada saat terjadinya puncak musim pemijahan.Research on the length distribution and population parameters of scalloped spiny lobster conducted in the Aceh Barat waters during April to November 2013. The aim of this study was to assess lobster fishery status in this waters from the point of view their length size and population parameters. Sampel collected randomly in the lobster landing site. Distribution of carapace length frequency was tabulated and analysed using logistic curve method. Length composition of male lobster was dominated under 72,5 mm midlenght, while female lobster was dominated above 72,5 mm midlength. This study found that the scalloped spiny lobster was caught before their reach the size of maturity (Lc = 65,8 mm < Lm = 76,8 mm). The peak season of spawning was indicated on May and August. Asimtotic length (CL∞) of scalloped spiny lobster was 119,5 mm with the growth rate (K) 0,39/year, total mortality (Z) 1,44/year, natural mortality (M) 0,67/year, and fishing mortality (F) 0,77/year. Exploitation rate was leading to the overfishing condition (E=0,54). Thus, it is needed to manage the lobster fishery in this area to gain the sustainability. We suggest that closing system season should be applied, especially in the peak spawning season.


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