数据缺乏条件下的渔业资源评估方法研究进展

全球范围内绝大多数渔业处于数据缺乏的状态,而常规的资源评估方法需要准确的生物学信息和完整的渔获数据,通常并不适合此类渔业资源的评估。数据缺乏方法(DLM)正是适用于此类情况的渔业资源评估方法,DLM的研究已经成为渔业资源研究的热点。作者对DLM的近期发展作了简要回顾,重点对主要的DLM方法和数据需求进行了分析比较,指出这些方法的应用需要注意的问题。历史渔获量是大多数DLM方法运用的必要数据(如DCAC、Catch-MSY模型),而关于资源丰度的相对指标和重要生活史参数(如种群内禀增长率、自然死亡系数),则是运用这些方法的必要补充。此外,对运用DLM所需的主要生物学参数的估算方法进行了简介。最后对DLM方法的使用及其在国内渔业中的运用提出了建议。     

鱼类自然死亡率的估算及其影响因子的探讨

为探讨鱼类自然死亡率参数,文中讨论了1种通过资源量和渔获量数据估算鱼类自然死亡率(M)的方法。蒙特卡罗模拟分析显示当资源量的白色噪音,即变异系数(CV)水平小于大约10％时自然死亡率的估计值基本上是准确的;捕捞死亡率的变化对自然死亡率估计的影响不大。文中构造了长寿命自然死亡率小和短寿命自然死亡率大的2个鱼类种群,模拟结果表明这种方法更适用于寿命短而自然死亡率大的种群。另外该方法在黄海鲲鱼(Engraulis japonicus)渔业数据上的应用同样得到了良好的结果。     

应用世代分析法估算鱼类自然死亡率的初步研究

根据已开发鱼类种群的自然死亡率（M）在鱼类资源评估中的重要作用,讨论了1种应用实际种群分析（VPA）（亦即世代分析方法）估算鱼类自然死亡率的方法.文中假设了捕捞努力量（E）已知和未知2种情况,并同时求出了其他种群参数,如可捕系数,补充量等.在蒙特卡罗模拟分析中,假设了4种模拟渔业（管理良好的渔业,掠夺式渔业,恢复性渔业和稳定性渔业）对该方法进行了验证.并将von-Bertalanffy生长方程（VBGF）引入VPA模型来估算鱼类的自然死亡率.当CV等于20%时,在4种模拟渔业中鱼类各龄自然死亡率（Ma）的EP均小于10%.在已知单位捕捞努力量渔获量数据时,计算北大西洋长鳍金枪鱼（Thunnus alalunga）的M等于0.119,这个结果比先前假定的值（0.3）小,但考虑到该鱼种所承受的高的捕捞压力作者认为该估计值是合理的.     

黄海南部春季蓝点马鲛(Scomberomorus niphonius)渔场海洋学特征与渔期渔场分布

以国家"973"项目资料和历史资料为基础,研究了黄海南部水域渔业海洋学特征、蓝点马鲛洄游行为及与渔场形成、渔期更迭关系.侧重分析2006和2007年春季水温年际变化对蓝点马鲛渔场、渔期分布的影响.结果表明,相对于2006年冷春,2007年黄海南部水域升温较早,渔汛盛期出现于4月25日,较2006年的5月1日左右明显提前,10℃等温线分布是早春南黄海蓝点马鲛鱼群分布与形成渔场的重要因子,而密集中心渔场往往出现于5月初;文中还讨论了南黄海大沙和吕泗渔场的性质特征,以期为蓝点马鲛渔情预报提供基础资料.     

黄渤海蓝点马鲛短期渔情预报的研究

本文报道了水文环境因子在生殖洄游群体的短期渔情预报中的应用,具体阐述了春汛水温、盐度、气温等因子与渔期及中心渔场的相关程度.预报的主要参考指标是:(1)利用4月上旬表层水温作为蓝点马鲛Scomberomorus niphoius(Cuvieret Valeniennes)初鱼期的预报因子,其准确率较高;(2)利用4月上旬表层水温10℃等温线的分布状况和位置,可作为判断蓝点马鲛中心渔场的范围和位置的重要指标.生产实践证明,1972年以来的十余年的蓝点马鲛汛期预报,正确率较高,此预报方法,在群众流网渔业中已得到普遍应用,取得了较佳的经济效益.     

基于耳石微结构的黄、渤海蓝点马鲛幼鱼日龄与生长

鱼类的生长是影响群体资源量的要素,研究鱼类的生长规律是开展资源评估工作的基础。本研究依据2016年9-10月和2017年8-10月在黄渤海采集的当年生蓝点马鲛(Scomberomorus niphonius)幼鱼,通过耳石微结构分析,确定了蓝点马鲛孵化期,建立了生长模型并估算了生长率。结果显示,幼鱼日龄范围为64~151 d,孵化日期为5月3日至6月15日,高峰期集中在5月20日至6月3日。叉长和体质量的生长符合Logistic生长模型。叉长平均绝对生长率和特定生长率分别为2.45 mm/d和0.85%/d,生长率随着日龄增大而小幅度减小。体质量平均绝对生长率和特定生长率分别为5.33 g/d和2.68%/d,最大绝对生长率和最大特定生长率分别出现在111~120 d和91~100 d。本研究表明,蓝点马鲛幼鱼生长随日龄发生变化,早期生长较以往进一步加快。     

环境因子对渔业资源评估的影响及研究进展——基于Citespace的计量分析

结合环境因子进行渔业资源评估是适应全球性气候变化挑战的重要手段。本文基于2000—2019年Web of Science数据库中与环境因子有关的渔业资源评估为研究主题的文献样本数据,采用Citespace计量软件,通过文献共被引分析、关键词共现,系统梳理了该领域的研究前沿与热点。结果表明：(1)环境在渔业资源评估中的补充量估算,模型优化,管理方案设置等多方面都有广泛应用;(2)环境对单一渔业产生的作用会通过食物网影响其他渔业的发展,该领域的研究对象也逐渐从单一渔业发展为多个渔业,这既考虑了物种之间的相互影响,又便于探讨全球渔业在应对气候变化下的共性;(3)数据收集和建模水平进一步提高,使得基于时空、生态等要素的模型应用日渐广泛,为科学有效的资源评估提供了技术支撑。建议今后该领域的研究可以积极开展跨学科交流,了解渔业资源变动的内在机制,合理量化环境气候因子,引入大数据、人工智能和区块链等新技术,建立健全资源环境监测体系,为渔业资源的可持续发展奠定基础。     

利用后向预报方法分析印度洋黄鳍金枪鱼资源评估模型

当前,对渔业资源评估模型的诊断与选择,主要依赖于模型对观察数据的拟合度,很少评价模型的预测能力、并将其作为评价渔业资源评估与管理质量的依据。为此,本文利用后向预报方法评价了印度洋黄鳍金枪鱼(Thunnus albacores)资源评估模型的预测能力,并在此基础上分析了印度洋黄鳍金枪鱼的资源评估与管理质量。研究表明,在利用贝叶斯剩余产量模型对印度洋黄鳍金枪鱼进行资源评估时,存在如下问题:(1)拟合较好的模型其预测能力较差;(2)利用不同时段数据拟合模型时,采用DIC(Deviance Information Criterion)选择的最佳模型缺少稳定性;(3)不同模型估计的TAC (Total Allowable Catch)存在较大差异。据此可以判断,利用贝叶斯剩余产量模型对印度洋黄鳍金枪鱼进行资源评估与管理效果较差。本研究结果表明:(1)利用后向预报方法可评价模型的预测能力、DIC选择模型的稳定性,从而能在一定程度上判断模型模拟的种群演化动态是否正确、资源评估结果是否存在问题;(2)利用后向预报方法可揭示评估结果的不确定性及其可能引起的渔业管理风险,从而有利于避免渔业管理风险、实现渔业管理目标。     

渤海蓝点马鲛食物链结构的研究

从60年代起,我国开始进行鱼类食性的研究(杨纪明、郑严,1962;杨纪明、林景祺，1966),并且开始以食性分析的方法,对特定海区内的鱼类食物关系进行研究(邓景耀等,1986;张其永等,1981),这为海洋食物链研究提供了初步资料。但至今尚未见有单种鱼食物链结构的研究报道。 蓝点马鮫 Scomberomorus niphonius (Cuvier et Valenciennes)为暖水性、洄游性、中上层鱼类。通常每年6月进入渤海产卵,11月前后离开渤海,向深海做越冬洄游(韦晟,1980)。蓝点马鲛作为渤海的重要经济鱼类之一,近些年来资源量一直保持相对稳定(韦晟,1982;朱德山、韦晟,1983)。进行蓝点马鲛的食物链研究,一方面有助于进行蓝点马鮫资源的预测、增殖及管理,另一方面对阐明渤海生态系统中的能量转换也具有一定意义。本文试图对蓝点马鲛食物链结构问题进行讨论。     

渔获量时间序列长度对基于CMSY方法的资源评估结果的影响

大多数渔业种类由于数据缺乏,无法使用传统的渔业资源评估方法开展评估和管理。越来越多的研究采用CMSY等基于有限数据的评估方法,但CMSY方法在渔获量数据时间序列长度有限、存在误差等情况下的评估可靠性尚有待验证。本研究运用CMSY方法对黄海3种产量较高的经济鱼类开展资源评估,探索渔获量数据时间序列长度、不同渔业发展阶段,以及观测误差水平对评估结果的影响。结果表明,鲐、带鱼和银鲳在2000年后均出现产量高于最大可持续产量(MSY)的情况,资源处于过度利用状况(B/B_MSY<1、 F/F_MSY>1),近10年来开发强度降低,但生物量仍处于较低水平(B/B_MSY<1)。评估模型的回溯性分析结果差异较小,表明评估结果稳定。从数据长度上看,使用遍历产量上升和下降过程的长时间序列数据,其评估结果更为稳定。在观测误差大于20%的情况下,模型对MSY和B_MSY出现高估,但结果仍较为稳健。在CMSY方法的应用中应注意选取长时间序列的产量数据,在评估结果不确定性高的情况下应采取相对保守的渔业管理措施。     

The impact of natural mortality variations on the performance of management procedures for Spanish mackerel(Scomberomorus niphonius) in the Yellow Sea,China

Natural mortality rate(M) is one of the essential parameters in fishery stock assessment, however, the estimation of M is commonly rough and the changes of M due to natural and anthropogenic impacts have long been ignored.The simplification of M estimation and the influence of M variations on the assessment and management of fisheries stocks have been less well understood. This study evaluated the impacts of the changes in natural mortality of Spanish mackerel(Scomberomorus niphonius) on their management strategies with data-limited methods. We tested the performances of a variety of management procedures(MPs) with the variations of M in mackerel stock using diverse estimation methods. The results of management strategies evaluation showed that four management procedures DCAC, SPMSY, cur E75 and minlen Lopt1 were more robust to the changes of M than others; however, their performance were substantially influenced by the significant decrease of M from the 1970s to 2017. Relative population biomass(measure as the probability of B0.5 BMSY) increased significantly with the decrease of M, whereas the possibility of overfishing showed remarkable variations across MPs. The decrease of M had minor effects on the long-term yield of cur E75 and minlen Lopt1, and reduced the fluctuation of yield(measure as the probability of AAVY15%) for DCAC, SPMSY. In general, the different methods for M estimation showed minor effects on the performance of MPs, whereas the temporal changes of M showed substantial influences. Considering the fishery status of Spanish mackerel in China, we recommended that cur E75 has the best trade-off between fishery resources exploitation and conservation, and we also proposed the potentials and issues in their implementations.     

Long-period variations in the optical and microphysical parameters of surface aerosol in a Moscow suburb

The mass concentration M of surface submicron aerosol and its condensation activity χ were measured at the Zvenigorod Scientific Station of the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, in 2001–2006. Variations in these quantities on scales of several days to several months are analyzed. It is shown that the occurrence of dense and superdense hazes over central Russia became more frequent during these years. This resulted in a change in the character of the seasonal dependence of the mass aerosol concentration M: ordered oscillations whose amplitude increases from year to year appeared in the seasonal cycle of M. Due to more frequent cases of dense and superdense hazes in 2002–2006, a significant monotonic increase is observed in the annual means of M. The annual mean of M increased more than twofold in 2005 (56 μm/m³) compared to 2001 (23 μm/m³). The time regimes of M and χ are characterized by variations with periods in the vicinity of 10, 20, and 40–50 days, as well as variations with longer periods within 70–100 days. In addition, the variability of mass concentration is of a strongly intermittent character. A cross-spectral analysis has shown that, on the whole, variations in M are coherent with those in χ. If the parameters M and χ vary on the same time scales, then, as a rule, variations in M lag behind variations in χ by several days. To understand the relationship between the parameters M and χ, special investigations, including studies of aerosol composition, are needed.     

太平洋褶柔鱼冬生群资源丰度变动对ENSO事件的响应研究

太平洋褶柔鱼为大洋性经济鱼种,具有一年生命周期,其资源变动受气候和海洋环境条件的显著影响。本研究根据日本提供的2003-2012年太平洋褶柔鱼冬生群体的渔业统计数据,结合产卵场环境数据以及尼诺指数ONI（定义为Niño 3.4区海表温度距平值）,分析不同气候条件下（厄尔尼诺和拉尼娜）太平洋褶柔鱼冬生群体产卵场海表温度（SST）、叶绿素a（Chl-a）浓度以及适宜产卵面积（SSA）的变动情况及对其资源丰度（CPUE）的影响。结果表明,太平洋褶柔鱼冬生群体产卵场SST、Chl-a浓度和SSA具有明显的季节性变化。相关分析表明,各年CPUE与Chl-a浓度以及SSA具有显著的正相关关系（p<0.05）,但与SST相关性不显著（p>0.05）。此外,厄尔尼诺和拉尼娜事件通过驱动太平洋褶柔鱼冬生群体产卵场SSA和关键海域（25°-29°N,122.5°-130.5°E）内的Chl-a空间分布和大小变化,从而改变其资源丰度,但影响作用随各异常事件的强度不同而变化,具体表现为：发生弱强度厄尔尼诺事件时,产卵场SSA较高,Chl-a浓度处于较低水平,导致资源补充量处于较低水平,CPUE降低;发生中等强度厄尔尼诺事件时,产卵场SSA较低,但Chl-a浓度处于较高水平,导致资源补充量增加,CPUE处于上升水平;发生中等强度拉尼娜事件时,产卵场SSA和Chl-a浓度均处于较高水平,资源补充量显著增加,CPUE显著升高。研究表明,厄尔尼诺和拉尼娜事件对太平洋褶柔鱼冬生群体产卵场摄食孵化环境和资源丰度变动具有显著影响。     

鱼耳石碳氧同位素在黄、渤海小黄鱼种群识别中的应用

Oxygen and carbon isotope ratios(δ~(18)O and δ~(13)C) in otoliths were used to identify the stock structure of small yellow croaker,Larimichthys polyactis.Otoliths were collected from fish at five locations across the Yellow Sea and the Bohai Sea representing most of their distributional range and fisheries areas.The significant differences in the isotopic signatures showed that the five locations could be chemically distinguished and clearly separated,indicating stock subdivision.Correlation of δ~(18)O and δ~(13)C values suggested that population of L.polyactis could be divided into the Bohai Sea group,the southern Yellow Sea group and the central Yellow Sea group.Discriminant analysis of δ~(18)O and δ~(13)C values demonstrated a high significant difference with 85.7% classification accuracy.The spatial separation of L.polyactis indicated a complex stock structure across the Yellow Sea and the Bohai Sea.These results indicate that optimal fisheries management may require a comprehensive consideration on the current spatial arrangements.This study has provided further evidence that measurement of the stable isotopes ratios in otolith can be a valuable tool in the delineation of fishery management units.     

Retrospective analysis of seismic regime features before the Taiwan earthquakes of 1999 and 2002

The features of the seismic regime before the strongest earthquakes of Taiwan in the late 20th (Chi-Chi on September 21, 1999, M_w = 7.6) and the early 21st century (March 31, 2002, M_w = 7.4) are analyzed. Based on 1990–1999 and 1994–2002 data, respectively, retrospective analysis of three seismic regime parameters are studied: the total annual number of earthquakes N_Σ in the range of M_L = 2.5–5.5 and M_w = 3.0–7.0; the total annual quantity of released seismic energy ΣE, J; and angular coefficient b of earthquake recurrence graphs. Two explicit subperiods are revealed in the course of the seismic regime: quiescence in 1990–1996 before the Chi-Chi earthquake and in 1994–1997 before the March 2002 earthquake; in 1997–1999 and 1998–2002, respectively, seismic activation is observed. Due to the predominance of weak earthquakes during the Chi-Chi earthquake preparation, factor b appeared relatively higher (–1.16 on average); in contrast, before the March 2002 earthquake, due to the occurrence of foreshocks with M_w = 6.8–7.0, the factor b values appeared relatively lower (–0.55 and–0.74 for the quiescence and activation subperiods, respectively). Despite the fundamental difference in the seismotectonic situation between the domains where two mainshocks occurred and significantly difference energy ranges of the initial seismic events, the analysis results are similar for both earthquakes. In both cases, the mainshock occurred at the peak of released energy, which can be considered a coincidence. Solid verification of this positive tendency requires the accumulation of seismological statistics.     

Variability of Particulate Organic Phosphorus in the Northwestern Part of the Black Sea

Based on long-term (1985–1995) monitoring data, the paper considers the peculiarities of seasonal variability in the spatial and vertical distribution of particulate organic phosphorus (Р_POM) in the surface layer and in the photosynthetic zone in the northwestern Black Sea. Regression equations, experimental data, and satellite observations for the chlorophyll a concentration allowed us to evaluate the seasonal longterm (1979–1995) variability in Р_POM in the surface layer and photosynthesis zone. The ratios of the concentrations of particulate organic carbon, nitrogen, phosphorus, and chlorophyll a are calculated and statistical estimates of seasonal changes in the Р_POM in the areas with different degrees of influence of river runoff and water of open seas are obtained. The consistency of intra-annual changes in the concentrations of Р_POM, chlorophyll a, and phytoplankton biomass is shown, which indicates the role of phytoplankton in the formation of Р_POM and in its intra- and interannual variability in the northwestern part of the sea. It is shown that long-term seasonal variations in Р_POM and related changes in the concentration of chlorophyll a depend on the variability of bulk river runoff, the extent of its abundance in the northwestern shelf, and regional hydrometeorological conditions.     

黄海小黄鱼生物学特征对多重压力的响应

Temporal changes in biological characteristics of small yellow croaker Larimichthys polyactis in the Yellow Sea were examined for the period of 1960–2008. The body size and age of small yellow croaker decreased substantially, in particular, average length of fish in 2008 was reduced by ~85% than those occurring in 1985, and at that time ~93% of the total catch was dominated by one-year-old individuals. Correspondingly, growth parameters also varied significantly over the years, i.e., k(growth coefficient) and t_0(zero-length age) gradually increased from 0.26 and –0.58 year in 1960 to 0.56 and –0.25 year in 2008, respectively. Although, L∞(body length)sharply decreased from 34.21 cm in 1960 to 24.06 cm in 2008, and t_r(inflexion age) decreased from 3.78 year in1960 to 1.61 year in 2008. There was a great increase both in natural mortality coefficient and fishing mortality coefficient. However, according to the gray correlation analysis, changes in the biological characteristics of small yellow croaker were induced by different stressors ranked as: fishing vessel powerfeeding gradesea surface temperature. This study suggests that the active fishery management measures for biological characters of fish populations should be considered.     

利用基于环境因子的动态产量模型评估西南大西洋阿根廷滑柔鱼

西南大西洋阿根廷滑柔鱼,Illex argentinus,巴塔哥尼亚南部群体是重要的经济种类。海洋环境因子在柔鱼资源分布中起着重要的作用。本研究利用基于环境因子的动态产量模型评估2000-2010年的滑柔鱼的资源量。假设海洋环境因子（滑柔鱼产卵场最适宜海表温度占比）影响动态产量模型的参数K,DIC值表明在正态分布和均匀分布下均是基于环境因子的评估模型优于基本的动态产量模型。阿根廷滑柔鱼的最大可持续产量（MSY）在351600吨到685 100吨之间,资源生物量在1322400吨到1 803 000吨之间,其捕捞死亡系数均小于F_0.1和F_MSY,资源处在良好状态,没有遭受过度捕捞。本研究为应用环境因子在柔鱼类的资源评估与管理提中供了科学的参考方法。     

High mortality and poor growth of green mussels, <Emphasis Type="Italic">Perna viridis</Emphasis>, in high chlorophyll-<Emphasis Type="Italic">a</Emphasis> environment

The current study was carried out from May 2014 to April 2015 to estimate the stock status of P. viridis in Marudu Bay. The gonad development was monitored by histological examination, while the population parameters including asymptotic length (L_∞), growth coefficient (K), mortality rate (Z, F and M), exploitation level (E) and recruitment of P. viridis were estimated using the lengthfrequency data. Results of the current study demonstrated that P. viridis in Marudu Bay spawned throughout the year with two major peaks, one in April to May and another one in October to December. The recruitment pattern was continuous with the peak in May to June 2014, which corresponded to the first spawning peak in April. However, no significant recruitment was observed from the second spawning peak due to the difference in spawning timing between male and female populations. The estimated asymptotic length (L_∞), growth coefficient (K), total mortality (Z), natural mortality (M), fishing mortality (F) and growth performance (ф) of P. viridis in Marudu Bay were estimate to be 117 mm, 0.97 yr^-1, 4.39 yr^-1, 1.23 yr^-1, 3.16 yr^-1 and 4.123, respectively. The exponent b of the lengthweight relationship was 2.4 and exploitation level (E) was 0.72. The high mortality, low condition indices and negative allometric of P. viridis in Marudu Bay is caused by a lack of suitable food in the surrounding water.     

Ring-Shaped Seismicity Structures in Southern California: Possible Preparation for Large Earthquake in the Los Angeles Basin

Some characteristics of seismicity in Southern California are studied. It is found that ring-shaped seismicity structures with threshold magnitudes M_th of 4.1, 4.1, and 3.8 formed prior to three large (M _w > 7.0) earthquakes in 1992, 1999, and 2010, respectively. The sizes of these structures are several times smaller than for intracontinental strike-slip events with similar magnitudes. Two ring-shaped structures are identified in areas east of the city of Los Angeles, where relatively large earthquakes have not occurred for at least 150 years. The magnitudes of large events which can occur in the areas of these structures are estimated on the basis of the previously obtained correlation dependence of ring sizes on magnitudes of the strike-slip earthquakes. Large events with magnitudes of M _w = 6.9 ± 0.2 and M _w = 8.6 ± 0.2 can occur in the area to the east of the city of Los Angeles and in the rupture zone of the 1857 great Fort Tejon earthquake, respectively. We believe that ring-structure formation, similarly to the other regions, is connected with deep-seated fluid migration.