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1.
《Fisheries Research》2008,89(1-3):51-55
Based on data series for 8 consecutive years of settlement of post-larvae of the California spiny lobster Panulirus interruptus, its relationship to commercial catch was examined. The purpose was to establish a database to build a model for prediction of commercial catches of this lobster. The study area is a rocky shelf southwest of the bay entrance of Bahía Tortugas in Baja California Sur. A set of artificial collectors was placed at this site to obtain postpuerulus and early juveniles settlement for each month. Different simple regression analyses were performed on annual series of mean rates of post-larval settlement vs. commercial catches by the Bahía Tortugas fishing cooperative. We tested several delay periods between the series (4–8 years to approximate the age of fishery recruitment) to find the best-fit relationship. The relationship with a 5-year delay showed the highest positive correlation (0.7925) and was statistically significant. This delay period was used to regress the data for the years 1993–2001. The results showed that variations in the abundance of settled post-larvae in a given year are reflected in the commercial catch 5 years later and exhibit the same upward or downward trend. The one exception was the high post-larval settlement rate in 1997–1998, coinciding with the El Niño event, which was not mirrored by a similar increase 5 years later in the 2002–2003 catch. The pre-recruit index seems a very promising tool for predicting catches for this lobster fishery. 相似文献
2.
The brown shrimp C. crangon supports a large commercial fishery in British, Belgian, Dutch, German and Danish waters. It produces eggs throughout the year with two seasonal peaks in summer and winter, respectively. Uncertainty exists with regard to the relative importance of the two egg production seasons for the mass invasion of juvenile recruits of 10–20 mm length in May/June, which is the dominant seasonal signal in the German and Dutch Wadden Sea, and which is presumed to grow into the exploitable stock by the autumn, causing the typical rise of commercial catches at that time of the year. A simulation model was developed that predicts the daily abundance of juvenile recruits attaining a given length, typically in the range of 10–20 mm. The model uses: (i) experimental data on the development times of eggs and larvae and the growth rates of juveniles; (ii) field data on the seasonal temperature cycle in different years (1986, 1992 and 1993 or mean conditions) and areas (German and Dutch Wadden Sea) of the North Sea; and (iii) a calculated index of the relative seasonal egg production intensity of adult C. crangon . Predictions of the simulations are compared with field observations on the seasonal occurrence of juvenile recruits in the German and Dutch Wadden Sea. Using temperature data from German waters, in the simulations peak recruitment was predicted to occur 1–2 months later than that observed in the field. However, if seasonal temperature data from Dutch waters were used, the predicted time of the first mass occurrence of recruits matched the field observations more closely. Simulations revealed that the first mass invasion of juveniles originates almost entirely from the winter egg production. It was also found that the simulated recruitment is condensed into a peak, which is narrower after a cold winter. 相似文献
3.
To include the effects of environmental factors on the production of small yellow croaker, Pseudosciaena polyactis Bleeker, in the Yellow Sea, we applied time series analysis to the commercial catch and salinity and temperature data for the period 1970 to 1988. Residuals from a weighted least-squares regression of log-transformed catches against year and month were calculated to remove not only seasonal factors but also long-term trends in catches. The residuals of mean and standard deviation (SD) of temperature and salinity were calculated and used for autocorrelation, cross-correlation and first-order autoregression analysis (AR(1)) using maximum likelihood. The landings showed a decreasing pattern across years with a conspicuous seasonal cycle within years. Catch residuals showed a strong positive autocorrelation and a conspicuous time-lagged cross-correlation with the residuals of mean and SD of seawater temperature at 75␣m. AR(1) revealed that positive anomalies of mean temperature were associated with positive anomalies in the production of small yellow croaker with a one year time lag. The decrease in the residual of SD of temperature appears to be related to the high production 0.5–1.0 year later. The effect of salinity was negligible compared with that of temperature. Therefore, the warm spawning period and homogeneous temperature condition of previous years for young fish may cause the increase in the following year's yield of this fish species. When used to predict catches in 1989 and 1990, the AR(1) model explained 40% of the variances of the observed landings. 相似文献
4.
An individual‐based model (IBM) for the simulation of year‐to‐year survival during the early life‐history stages of the north‐east Atlantic stock of mackerel (Scomber scombrus) was developed within the EU funded Shelf‐Edge Advection, Mortality and Recruitment (SEAMAR) programme. The IBM included transport, growth and survival and was used to track the passive movement of mackerel eggs, larvae and post‐larvae and determine their distribution and abundance after approximately 2 months of drift. One of the main outputs from the IBM, namely distributions and numbers of surviving post‐larvae, are compared with field data as recruit (age‐0/age‐1 juveniles) distribution and abundance for the years 1998, 1999 and 2000. The juvenile distributions show more inter‐annual and spatial variability than the modelled distributions of survivors; this may be due to the restriction of using the same initial egg distribution for all 3 yr of simulation. The IBM simulations indicate two main recruitment areas for the north‐east Atlantic stock of mackerel, these being Porcupine Bank and the south‐eastern Bay of Biscay. These areas correspond to areas of high juvenile catches, although the juveniles generally have a more widespread distribution than the model simulations. The best agreement between modelled data and field data for distribution (juveniles and model survivors) is for the year 1998. The juvenile catches in different representative nursery areas are totalled to give a field abundance index (FAI). This index is compared with a model survivor index (MSI) which is calculated from the total of survivors for the whole spawning season. The MSI compares favourably with the FAI for 1998 and 1999 but not for 2000; in this year, juvenile catches dropped sharply compared with the previous years but there was no equivalent drop in modelled survivors. 相似文献
5.
Daisuke Yamanaka Kazumi Sakuramoto Naoki Suzuki Tohru Nagasawa 《Fisheries Science》2007,73(4):837-844
Catch forecasting and the relationship between water temperature and catch in the snow crab Chionoecetes opilio in the western Sea of Japan were investigated. Catch was used as an index of abundance on the basis of high correlations
between catch per unit effort for the period when the latter data were available. The pattern of fluctuations, in catches
and index coincided well with each other. Therefore, catch data were regarded as an index of abundance and the correlation
coefficient between catch and water temperature was calculated at several depths from 1964 to 1999. Catch forecasting models
were composed using significantly correlated variables with the following results: (i) in April and September, the catch showed
high positive correlation with water temperatures (depth 50, 100, and 200 m, time lag 4–6 years); and (ii) a model using water
temperatures in April alone (depth 100 m, time lag 4–7 years) forecasted the catches with a coefficient of determination of
0.504, where models using more variables (water temperatures in the 2 months and catches) showed a coefficient of 0.587 at
most. Environmental conditions during the early life stages of the snow crab are thought to deeply influence the fluctuations,
in abundance. 相似文献
6.
Climate–ocean regimes in the north-east Pacific translate into decadal-scale patterns in the relative success of sablefish ( Anoplopoma fimbria ). By combining estimates of year class abundance determined from commercial catches and research surveys for adults and juveniles, we were able to construct an index of year class success. Year classes from 1960 to 1976 were generally below average, with little indication of good year class success. The 1977 year class was exceptionally large and year classes from 1978 to 1990 were generally above average. Year classes following 1990 were generally below average. The periods with above-average year classes were generally characterized by intense Aleutian Lows, above-average frequency of south-westerly winds and warmer coastal sea surface temperatures off the west coast of Vancouver Island. Decadal-scale patterns in the production of sablefish suggest stability in long-term periods of similar recruitment but different mean levels of productivity across periods. However, rapid shifts between periods remain unpredictable and therefore complicate the incorporation of decadal-scale dynamics in management. 相似文献
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9.
A review of seed production and stock enhancement for commercially important portunid crabs in Japan
Katsuyuki Hamasaki Yasuhiro Obata Shigeki Dan Shuichi Kitada 《Aquaculture International》2011,19(2):217-235
We reviewed the present status of seed production for stock enhancement and evaluated the impact of stocking on commercial
catches in Japan, of portunid crabs particularly Portunus trituberculatus and Scylla paramamosain. The mean survival rate from hatching to first-stage crabs was around 10%, and 20–30% of the larval culture trials conducted
in recent years could not harvest juveniles during seed production. To achieve reliable mass seed production technologies,
measures for controlling disease and the nutritional condition of larvae in seed production tanks are required to be developed.
The main spawning season extends from April/May to July. Reflecting their life cycle characteristics such as high growth rates,
crabs recruit to the fishery after September and largely contribute to the commercial landings until December in the hatching
year. The main release season of juveniles is from June to July. Consequently, released juveniles are expected to contribute
to commercial landings in the release year. Analyses of catch and release statistics in two small bays estimated the yield
from released individuals (YPR, yield per release) at 2.4 g for P. trituberculatus and 3.3–7.7 g for S. paramamosain, which were similar to values reported from tagging surveys. On a major regional basis, catch and release histories of P. trituberculatus highlighted the impact of hatchery releases on commercial landings as 33.6 g YPR in the Seto Inland Sea, where catches and
releases have been greatest. Although the YPR estimates were different between small bays and major regional seas, Japanese
stock enhancement programmes should have had an impact on portunid crab production, dependent on the magnitude of the releases. 相似文献
10.
江苏沿岸定置张网主要渔获组成以及对经济鱼类幼体的损害分析 总被引：1，自引：0，他引：1
深水张网是吕四渔场传统的作业方式,渔获量占江苏省海洋捕捞总量的比重较大。根据2004年4月~2005年11月吕四渔场深水张网渔业监测资料,结合渔业统计数据,分析了该渔业渔获物种类组成及其季节变化,以及主要经济鱼类渔获物种类组成和幼鱼比例。结果表明,各季节深水张网优势渔获物种类组成具有明显的季节变化特征,春季主要以小黄鱼、黄鲫、焦氏舌鳎和葛氏长臂虾为主,夏季为小黄鱼、黄鲫、焦氏舌鳎和银鲳,秋季为小黄鱼、焦氏舌鳎、棘头梅童鱼、灰鲳和银鲳,冬季为小黄鱼、焦氏舌鳎、棘头梅童鱼和斑鰶;小黄鱼和焦氏舌鳎是深水张网渔业常年优势渔获物。主要经济鱼类小黄鱼以6月份平均网产最高,但主要以幼鱼为主,2004年和2005年的平均体重分别仅0.81 g/ind和1.04 g/ind,幼鱼渔获尾数分别占到99.1%和99.8%,累计损害幼鱼尾数分别达1.84×107ind和2.37×107ind;银鲳平均体重3.22 g/ind和3.8 g/ind,累计损害幼鱼尾数分别为4.84×105ind和4.41×105ind。建议对深水张网渔业加强管理,可对该渔业提前一个月休渔,提高网囊网目尺寸,并强化管理力度。 相似文献
11.
A review of the distribution, ecology and population dynamics of age-0 walleye pollock in the Gulf of Alaska 总被引：1，自引：0，他引：1
This review paper synthesizes published research and unpublished data on the abundance and distribution patterns, ecology and population dynamics of walleye pollock ( Theragra chalcogramma ) during their first year of life (age-0) in the Gulf of Alaska. Distribution patterns have been described using mainly trawl catches, but recently, acoustic methodology has been employed, especially in examining vertical distributions. Although age-0 pollock are found throughout the Gulf, the highest catches occurred west of Kodiak Island. Pollock are pelagic for at least their first 6 months of life but show an ontogenetic increase in depth distribution superimposed on a pronounced diel vertical migration at a larger size. Daily growth rates are variable depending on year, season and area, and growth generally ceases during the winter. The diet of age-0 pollock shifts from mainly copepods in early juveniles to euphausiids by fall, with epibenthic organisms becoming important during the winter months. Feeding occurs mainly at night in surface waters. Age-0 pollock are most frequently associated with gelatinous zooplankton (medusae) and older pollock. Many predators on age-0 pollock have been identified; the most important are arrowtooth flounder ( Atheresthes stomias ), adult pollock, puffins ( Fratercula spp.), murres ( Una spp.), harbor seals ( Phoca vitulina richardsi ) and Steller sea lions ( Eumetopiasjubatus ). Modelling provides some insight into the population dynamics of these juveniles and environmental conditions which interannually affect their survival. These results are discussed relative to the importance of age-0 pollock in the recruitment of this species and to their role in the pelagic ecosystem. 相似文献
12.
帆张网渔获物组成及其多样性分析 总被引：2，自引：0，他引：2
根据2007年12月～2008年6月在东海北部和黄海南部海域调查所获取的资料,分析了帆张网作业渔获物组成及其多样性特征。结果显示,调查采获的鱼类41种,甲壳类22种,头足类3种。其中主要渔获物由小黄鱼（Pseudosciaena polyactis）、带鱼（Trichiurus haumela）、细条天竺鱼（Apogon lineatus）、太平洋褶柔鱼（Todarodes pacificus）、长枪乌贼（Loligo bleekeri）和细点圆趾蟹（Ovalipes punctatus）等10个种类组成,其质量占总样品质量的79.86%。对小黄鱼和带鱼进行体长和体质量组成分析得出,其幼鱼比例分别为97.20%和61.00%。物种种类丰度和多样性指数值显示,鱼类1月较高,而4、5和6月相对较低;甲壳类在5月较高,而4月相对较低。现行的帆张网渔获物中幼鱼比例较高,对经济幼鱼资源的损害较严重。 相似文献
13.
J. M. EIIiott 《Ecology of Freshwater Fish》1992,1(1):5-11
Abstract– Analysis of annual rod and commercial catches of adult seatrout demonstrated strong positive relationships between large-scale spatial variance (S2s, variation in catches between rivers for each year) and spatial mean density (x?s, mean catch per year), and also between temporal variance (S2t, variation in catches between years for each river) and temporal mean density (x?t, mean catch for each river). Both relationships were described by a power function, s2=ax-b. For spatial variability, there were no significant differences between power functions for both rod and commercial catches from the North West, Welsh and South West regions. As the power b was not significantly different from two, relative spatial variability (measured by coefficients of variation (CV)) was fairly constant between years. Significantly higher values of b were obtained for the Wessex (GM b= 2.233) and North East (GM b=2.824) regions, and therefore the increase in CV with mean annual catch was significant but slight for Wessex rivers and marked for North East rivers. For temporal variability, there were no significant differences between power functions for both rod and commercial catches from all 5 regions and therefore a common power function was fitted to the data from all 67 rivers. As the power b was significantly less than two (GM b= 1.729), relative temporal variability (measured by CV) decreased significantly with increasing mean catch per river. Some limitations and implications of this analysis are discussed. Similar results from different regions for both rod and commercial catches suggest that such data do reflect adult population density, in spite of the different methods used to catch the sea-trout, variations in fishing effort and failures to report catches. The analysis of temporal variability provides a basis for classifying the major sea-trout rivers according to their mean annual catch and their relative variability in catches between years (using the CV). 相似文献
14.
M. S. Busby J. T. Duffy‐Anderson K. L. Mier L. G. De Forest 《Fisheries Oceanography》2014,23(3):270-287
Larval and early juvenile fishes were sampled from the eastern Bering Sea (EBS) shelf from 2001 to 2005, and in 2007. Data from these collections were used to examine spatial and temporal patterns in species assemblage structure and abundance. The years 2001–2005 were unusual because the EBS water temperature was ‘warm’ compared with the long‐term mean temperature. In contrast, 2007 was a ‘cold’ year. The abundance of the five most numerous taxa at 12 stations common to all years sampled (1996–2005, 2007) were significantly different among years. Larval and early juvenile stage Theragra chalcogramma (walleye pollock), a commercially important gadid, were by far the most abundant fish in all years. Bottom depth alone best explained assemblage structure in most years, but in others, bottom depth and water column temperature combined and percent sea‐ice coverage were most important. Abundance of T. chalcogramma larvae increases with water column temperature until 5°C and then becomes level. Higher abundances of Gadus macrocephalus (Pacific cod) larvae occur in years with the greatest percent sea‐ice cover as indicated by GAM analysis. Larvae of Lepidopsetta polyxystra (northern rock sole) increase in abundance with increasing maximum wind speed, but decrease at a later date during the last winter storm. The data are consistent with the hypothesis that oceanographic conditions, specifically water temperature and sea‐ice coverage, affect the spatial and temporal pattern of larval abundances. In general, ichthyoplankton species assemblages can be important early indicators of environmental change in the Bering Sea and potentially other subarctic seas as well. 相似文献
15.
Claus Reedtz Sparrevohn Martin Lindegren Brian R. Mackenzie 《Fisheries Oceanography》2013,22(5):400-408
The consequence of elevated ocean temperatures on commercial fish stocks is addressed using time series of commercial landings (1906–2004) and juvenile survey catch data (1904–2006) collected around Denmark. We analyze (i) whether warm‐water sole (Solea solea) has increased relative to Boreal plaice (Pleuronectes platessa) and (ii) whether two related warm‐water species (turbot, Psetta maxima and brill, Scophthalmus rhombus) show similar responses to increasing temperature or, alternatively, whether turbot (which has a broader juvenile diet) has been favored. Since the early 1980s, both sole and turbot have constituted an increasing part of the commercial landings and survey catches, as compared with plaice and brill, respectively. These changes in species composition were linked to sea surface temperatures, Northern Hemisphere temperature anomalies (NHA) and the North Atlantic Oscillation. NHA was closely related and explained 43% of the observed variation in sole survey catches relative to the plaice catches and almost 38% of the observed variation in the sole landings relative to the plaice landings. For the less common species, turbot and brill, none of the global change indicators explained more than 15% of the variation, although all showed a positive relationship. Survey catch per unit effort increased significantly for both sole and turbot around the early 1980s, whereas catch per unit effort for plaice and brill remained constant. The results indicate that the abundance of warm‐water species is likely to increase with increasing temperature but also that species with similar life histories might react differently according to degree of specialization. 相似文献
16.
KEVIN M. BAILEY ANNETTE L. BROWN MARY M. YOKLAVICH KATHRYN L. MIER 《Fisheries Oceanography》1996,5(S1):137-147
Interannual variability in growth of larval walleye pollock Theragra chalcogramma was examined from 1983 to 1991 and of juveniles from 1985 to 1990. ANCOVA was used to assess differences in population growth rates, and an alternate method was developed to examine variations between annual length-at-age data and average 'expected' values over different age groupings. For larvae, the years 1986, 1987, 1989 and 1990 had higher than average length-at-age, and 1988 and 1991 had lower than average values. Relationships between growth and SST and larval density were not clear. A tentative relationship between copepod nauplii abundance and larval length-at-age was noted. The consequence of larval growth to larval mortality, late larval abundance or recruitment was not clear. We conclude that larval mortality rates are highly variable and tend to mask effects of moderate variability in growth on later abundance. For juveniles, 1987 had significantly lower than average length-at-age and 1988 had higher than average values. Although there are few years of data, they tend to support the importance of juvenile growth in the recruitment process. Conditions for the large 1988 year class are documented and discussed, including warm SST, calm winds, relatively low larval growth rates, low abundances of potential predators on larvae, low larval mortality rates, and high juvenile growth rates. 相似文献
17.
Abstract– We determined the habitat use of age-0 yellow perch ( Perca flavescens ) in two South Dakota (USA) lakes. Larval perch abundance was based on trawl catches and related to environmental variables on two late spring dates. Juvenile perch abundance was based on late July shoreline seine and bottom trawl catches. Day and night juvenile abundance relations to environmental variables were examined. Larval abundance appeared to be related to biological environmental variables, and no significant (P≥0.05) correlations with physical habitat variables were found. Juvenile yellow perch abundance was related to physical variables, particularly substrate, water temperature and water depth. The only biological variable that could be related to juvenile abundance was chironomid abundance. Finally, juvenile perch abundance was positively associated with abundance of other juvenile fishes and minnows, but these associations varied by lake, time of day and habitat type. Understanding age 0 perch habitat use will allow fishery biologists to better assess sampling designs and recruitment processes. 相似文献
18.
Scott G. Blair Chelsea May Brian Morrison Michael G. Fox 《Ecology of Freshwater Fish》2019,28(2):200-208
To determine whether invasive round goby (Neogobius melanostomus) from Lake Ontario were establishing a year‐round population in a tributary stream or migrating to the lake, we assessed population and individual movement patterns using mark–recapture assessment generated from weekly backpack electrofishing from May until November 2016. Round goby abundance was low in spring, peaked in summer and decreased again in autumn, suggesting seasonal inward stream migration and outward migration back to the lake. Adult round goby movement patterns were positively associated with changes in water temperature, but this was not the case for juveniles. Juveniles displayed a preference for shallow, upstream habitats. Observations of reproductive individuals coupled with a peak in juvenile abundance following the peak in adult abundance indicate that the tributary was used for reproduction and recruitment. The individual movement was primarily upstream in spring, and there was little net movement in summer, likely during reproduction. Downstream movement occurred in autumn over a short time period, suggesting rapid outmigration to the lake. The combined observations of seasonal population structure and individual movement suggest that tributary streams connected to large, infested waterbodies can be used for round goby reproduction and recruitment, rather than year‐round residence. This study provides evidence of round goby seasonal migration and their individual movement patterns within tributary streams, which complements an earlier study in Lake Erie tributaries and may be a common occurrence in other Great Lakes tributaries. 相似文献
19.
Climate has been linked to variation in marine fish abundance and distribution, but often the mechanistic processes are unknown. Atlantic croaker (Micropogonias undulatus) is a common species in estuarine and coastal areas of the mid‐Atlantic and southeast coasts of the U.S. Previous studies have identified a correlation between Atlantic croaker abundance and winter temperatures in Chesapeake Bay, and have determined thermal tolerances of juveniles. Here we re‐examine the hypothesis that winter temperature variability controls Atlantic croaker population dynamics. Abundance indices were analyzed at four life history stages from three regions along the east coast of the U.S. Correlations suggest that year‐class strength is decoupled from larval supply and is determined by temperature‐linked, overwinter survival of juveniles. Using a relation between air and water temperatures, estuarine water temperature was estimated from 1930 to 2002. Periods of high adult catch corresponded with warm winter water temperatures. Prior studies indicate that winter temperature along the east coast is related to the North Atlantic Oscillation (NAO); variability in catch is also correlated with the NAO, thereby demonstrating a link between Atlantic croaker dynamics, thermal limited overwinter survival, and the larger climate system of the North Atlantic. We hypothesize that the environment drives the large‐scale variability in Atlantic croaker abundance and distribution, but fishing and habitat loss decrease the resiliency of the population to periods of poor environmental conditions and subsequent weak year classes. 相似文献
20.
A. L. Shanks 《Fisheries Oceanography》2013,22(4):263-272
For 12 yr (1997–2001, 2006–2012) daily abundance of Cancer magister megalopae was measured in Coos Bay, Oregon. Before 2007 from 2000 to 80 000 megalopae were caught annually. In 2007, catch jumped and has since varied from 164 000 to 2.3 million. The step change in catch size appears related to a shift to negative Pacific Decadal Oscillation (PDO) values. Late season catches, which cannot be due to local spawning, are negatively correlated to the PDO, suggesting that these megalopae derive from north of the California Current. During periods of lower and higher catches, annual returns of megalopae were significantly negatively correlated to the day of the year of the spring transition and positively correlated to the amount of upwelling during the settlement season. The size of the Oregon commercial catch lagged 4 yr to allow for growth of recruits into the fishery is set by the number of returning megalopae; the relationship is parabolic. At lower returns, the population is recruitment limited, but at higher returns, density‐dependent effects predominate and set the commercial catch. Lagged commercial catches in Washington and Northern and Central California were also related to the number of megalopae returning to Coos Bay, suggesting that the forces causing variation in larval success are coast wide. If high return rates are due to a PDO regime shift, then for years to decades the commercial catch may be set by density‐dependent effects following settlement and the huge numbers of returning megalopae may impact benthic community structure. 相似文献