桑沟湾大叶藻附着生物的季节变化

2008年9月～2009年8月,对桑沟湾楮岛海域大叶藻叶片上的附着生物进行了周年调查,以期为我国浅海生态系中大叶藻等海草生态功能的研究提供基础资料。调查共记录大叶藻附着生物29种。附着的主要种类有盾卵形藻Cocconeis scutellum及其小型变种C.scutel lumvar.pava,褐毛藻Halothrixlumbricalis、点叶藻Punctaria latifolia、锈凹螺Chlorostoma rustica、Australaba sp.、脆螺Stenotis sp.。在春季,大叶藻上的附着硅藻类有9种,大型海藻类7种,动物类8种。其中,褐藻类为主要附着生物,附着高峰出现在4月份。夏季,附着的大型海藻种类明显减少,仅出现4种,而动物类有6种,硅藻类8种。其中,腹足类为夏季附着优势种。硅藻附着高峰出现在秋季,此时的附着动物类减少至4种,大型藻类种数与夏季持平,但附着的生物量较小。冬季未发现附着的大型海藻及动物,仅有微藻类的硅藻附着。     

不同栽培方式对鳗草实生苗建成和生理的影响

在15 ℃条件下,研究了3种栽培方式(水培促萌+萌中插植、水培促萌+萌后插植以及基质栽培)对鳗草(Zostera marina)种子萌发、实生苗建成与生长的影响,分析了鳗草实生苗的培育成本及其应对不同栽培方式的生理响应。结果显示,水培促萌+萌中插植、水培促萌+萌后插植的鳗草种子萌发率和实生苗建成率无显著差异(P>0.05),平均达到54.8%和46.5%,分别是基质栽培处理组的1.3和1.6倍(P<0.05)。水培促萌+萌中插植、水培促萌+萌后插植的鳗草实生苗的各项生长指标亦无显著差异(P>0.05),其平均值均显著高于基质栽培处理组(P<0.05),特别是根生成速率平均达到基质促萌处理组的1.6倍。主成分分析显示,水培促萌+基质插植的鳗草实生苗生理状态较优,其中,总氮和可溶性糖含量的贡献度较大,贡献度平均分别达到16.6%和15.0%,是基质栽培处理组的1.2倍(P<0.05)。培育成本分析显示,水培促萌+萌后插植栽培方式的培育成本最低(3.6元/株),是水培促萌+萌中插植栽培方式的81.9%。综合实生苗培育效果和培育成本,水培促萌+萌后插植的栽培方式是适宜的鳗草实生苗栽培方式,其主要通过提升实生苗非结构性碳水化合物的形成和提高光合色素含量,实现对实生苗建成与生长的促进作用。     

赤霉素和弱酸对鳗草种子萌发和生理特性的影响

本文研究了赤霉素和弱酸对鳗草(Zostera marina)种子萌发和生理特性的影响,监测了鳗草种子的累积萌发率、幼苗建成率以及种子萌发过程中种子干重、水分、呼吸速率、可溶性糖、淀粉、赤霉素、脱落酸含量和α-淀粉酶、β-淀粉酶活性的动态变化,探究了2种外源处理对鳗草种子的促萌作用,分析了鳗草种子应对外源促萌的生理响应过程。结果显示,2种促萌处理均能有效促进鳗草种子萌发和幼苗建成,其中,赤霉素处理组促萌效果最优,其种子萌发率和幼苗建成率为对照组的1.6倍;促萌期间,2个促萌处理组种子α-淀粉酶活性呈先上升后下降的趋势,淀粉含量呈下降趋势,可溶性糖含量呈持续上升趋势;至实验结束时,赤霉素处理组种子可溶性糖含量最高,是促萌前初始值的3.3倍,亦显著高于弱酸处理组和对照组(P<0.05),弱酸处理组种子淀粉含量最低,显著低于其他2组(P<0.05),而各处理组之间种子的α-淀粉酶活性无显著差异(P>0.05);主成分分析显示,种子α-淀粉酶活性、淀粉和可溶性糖含量为种子萌发过程中的关键因子。综合分析认为,外源赤霉素处理是破除鳗草种子休眠的有效方法,其主要通过调节种子淀粉酶活性、提高淀粉分解速率和提高可溶性糖含量为种子萌发提供能量实现破除休眠的作用。本研究结果为鳗草种子快速萌发技术提供了理论依据和科学基础。     

不同水体浊度对鳗草存活、生长和生理的影响

海水浊度升高是导致海草床退化的主要因素之一。通过3个月的室内实验,研究了不同水体浊度[2 (对照)、10、20、30和40 NTU]对鳗草存活、生长和生理的影响。结果显示,3个月后,鳗草植株的存活率随水体浊度升高呈现逐渐降低趋势,10~40 NTU处理组植株存活均显著低于对照组(P<0.05),至40 NTU处理组,植株存活率仅为对照组的56.1%;随水体浊度升高,植株的生长速率和生产力亦呈现下降趋势,至40 NTU处理组,植株茎节延伸速率和叶片延伸速率达到最小值,分别下降至对照组的48.9%和61.6%,地上生产力和地下生产力与对照组相比下降了64.6%和78.8%;相关性分析表明,长期浊度胁迫主要是通过影响植株非结构性碳水化合物含量,进而对植株生长存活产生负面影响。植株非结构性碳水化合物含量随水体浊度增加而逐渐下降,10~40 NTU处理组植株碳水化合物含量均显著低于对照组(P<0.05),各浊度升高处理组植株地上组织可溶性糖含量相比对照组降低了20.2%~74.7%。研究表明,水体浊度长期升高导致鳗草植株非结构性碳水化合物显著下降,对鳗草的生长存活不利。本研究为阐明鳗草海草床退化机理和选划适宜修复区等提供了理论依据。     

Don't go breaking apart: Anthropogenic disturbances predict meadow fragmentation of an endangered seagrass

1. Although it is well established that human activities are linked to the loss of seagrasses worldwide, the influence of anthropogenic disturbances on the habitat fragmentation of seagrass meadows is less understood. This information is essential to identify how humans are modifying seascapes and what disturbances pose the greatest risk to seagrasses, which is pertinent given the rapid urbanization occurring in coastal areas.
2. This study examined how the habitat fragmentation of an endangered seagrass Posidonia australis varied in relation to several anthropogenic disturbances (i.e. human population, marine infrastructure, terrestrial run-off and catchment land-usage) within 10 estuaries across 620 km of coastline in New South Wales, Australia.
3. When comparing between estuaries, the fragmentation of P. australis meadows was significantly greater in estuaries adjacent to highly populated metropolitan centres – generally in the Greater Sydney region. At sites within estuaries, the density of boat moorings was the most important predictor of habitat fragmentation, but there was also evidence of higher fragmentation with increased numbers of jetties and oyster aquaculture leases.
4. These results suggest that the fragmentation of seagrass meadows will become more pervasive as the human population continues to grow and estuarine development increases. Strategies to mitigate anthropogenic disturbances on seagrass meadow fragmentation could include prohibiting the construction of boat moorings and other artificial structures in areas where seagrasses are present or promoting environmentally friendly designs for marine infrastructure. This knowledge will support ongoing management actions attempting to balance coastal development and the conservation of seagrasses.

     

Overlaps in habitat use of fishes between a seagrass bed and adjacent coral and sand areas at Amitori Bay, Iriomote Island, Japan: Importance of the seagrass bed as juvenile habitat

ABSTRACT:   To clarify faunal overlap between a seagrass bed and adjacent coral and sand areas, and the number of reef fishes utilizing the seagrass bed as juvenile habitat, visual censuses were conducted at Amitori Bay, Iriomote Island, Japan. The numbers of species and individuals of fishes were significantly higher in the coral area than in the seagrass bed and sand area. Cluster and ordination analyses based on the number of individuals of each species demonstrated that the fish assemblage structure differed among the three habitats in each season, but with some overlaps. Approximately half the seagrass bed fishes occurred in the adjacent coral area (coral–seagrass species). Dominant species of coral–seagrass species utilized the seagrass bed as an important juvenile habitat. Thus, some overlaps in habitat use were present between the seagrass bed and adjacent coral area. Despite such overlaps, however, coral–seagrass species accounted for only approximately 15% of coral reef fishes overall, indicating that most of the latter hardly utilize the seagrass bed directly in the study area.     

鳗草根际固氮菌的分离鉴定及培养条件的筛选

为了解鳗草(Zostera marina)根际微生物的共生固氮功能,并分离得到对海草有潜在促生效果的功能微生物,以山东荣城天鹅湖鳗草为研究对象,采用选择性固氮培养基从其根际分离得到了两株具较高固氮酶活性的菌株(3A和4G),从形态学、生理生化特性、16S rDNA和固氮基因nifH等方面对菌株进行筛选和鉴定,探讨菌株的最佳培养条件并获得了菌株典型生长曲线。结果表明,菌株3A为海旋菌(Thalassospira),革兰氏阳性菌,菌落圆形桔黄色,可利用的碳源:D-甘露糖,D-松三糖,L-鼠李糖等,最佳培养条件:盐度2.585%,pH 8.18,温度31.49℃;菌株4G为芽孢杆菌(Bacillus),革兰氏阴性菌,菌落圆形乳白色,可利用的碳源:D-纤维二糖,D-葡萄糖,D-麦芽糖,蔗糖,D-甘露醇,D-海藻糖等,最佳培养条件:盐度2.920%,pH 7.99,温度37.27℃。利用乙炔还原法测定二者的固氮酶活性,分别为252.21 nmol C_2H_4/(mL·h)和196.31 nmol C_2H_4/(mL·h)。研究证实两株菌株具有良好的固氮性能,可用于海草固氮肥的研制,在海草床生态系统恢复研究领域具有潜在的应用前景。     

刺参围堰养殖中大叶藻的生态功能

为阐明围堰池塘内海草——大叶藻的生态功能并为将其引入刺参池塘养殖提供理论基础,对大叶藻区和裸露砂质底质区的温度、溶氧进行了比较测定,对刺参及其食物组成的同位素进行了分析,并与邻近自然海域草场系统进行对比。结果显示,春夏季大叶藻区底部温度比裸露砂质底质区温度低约0~0.33°C;0~25%的低大叶藻盖度下,海草区和裸露底质区溶氧差异不显著,50%~100%的中高盖度下,海草区表层溶氧显著高于裸露底质区,高约0.12~0.62 mg/L,底层溶氧低于裸露底质区,约0~0.38 mg/L;春季末,该海草环境下的刺参δ13C和δ15N比值分别为–15.27‰和8.11‰,具有与相邻自然草场系统中刺参明显不同的同位素特征值(–20.12‰和10.95‰)。混合模型的分析表明,其食物组成中来自大叶藻的贡献约为13%~52%,高于底栖硅藻(4%~49%)、悬浮颗粒有机物POM(23%~39%)以及附着生物(0~22%)。而邻近的自然草场中,来自POM和褐藻海蒿子的食物贡献最大,0.95置信水平下的置信区间(CI)分别为24%~54%和1%~53%,而海草丛生大叶藻的贡献为0~27%。本研究表明,大叶藻可以在一定程度上降低夏季池塘底部水温,增加水体溶氧,同时为刺参提供重要的食物来源,这在池塘组成相对简单的环境下是尤为重要的。     

Dispersal ability determines the genetic effects of habitat fragmentation in three species of aquatic insect

• 1. The dispersal ability of species and the geographic scale of habitat fragmentation both may influence the extent of gene flow between fragments, but their interactions have rarely been tested, particularly among co‐occurring species.
• 2. Population genetic structures of three species of aquatic insect were compared in streams fragmented by reservoirs and in unfragmented streams in north‐eastern Japan, using 52, 37, and 58 RAPD markers. The three species studied included a strong disperser Cincticostella elongatula (Ephemeroptera: Ephemerellidae), an intermediate disperser Stenopsyche marmorata (Trichoptera: Stenopsychidae), and a weak disperser Hydropsyche orientalis (Trichoptera: Hydropsychidae).
• 3. The patterns of genetic isolation by distance (IBD) supported a priori hypotheses of dispersal ability. The strong disperser (C. elongatula) exhibited significant IBD only at the largest spatial scale studied (among drainages, r=0.50, P<0.01). The intermediate disperser (S. marmorata) showed IBD both within (r=0.22, P<0.01) and among (r=0.45, P<0.01) drainages. The weak disperser (H. orientalis) did not exhibit significant IBD at any scale.
• 4. Pairwise genetic differentiation (θ) indicated that neither the weak disperser nor the strong disperser were genetically differentiated above and below reservoirs when compared with reference sites. This was in contrast to previous results for S. marmorata, for which subpopulations were genetically fragmented across larger (>4.1 km), but not smaller (<2.9 km) reservoirs.
• 5. We suggest that intermediate dispersers, i.e. those at equilibrium between migration and genetic drift within drainages, are more likely to be affected by fragmentation than either strong or weak dispersers. Intermediate dispersers could therefore be used as indicator species in studies aimed at detecting the effects of distance between habitat fragments (e.g. reservoir size) for conservation planning. Copyright © 2010 John Wiley & Sons, Ltd.

     

鳗草根际溶磷微生物分离、筛选及其对鳗草生长的影响

为明确鳗草(Zosteramarina)根际溶磷微生物溶磷能力及其对鳗草生长的影响,采用选择性无磷培养基从鳗草根际土壤中分离获得4株具较高溶磷能力的菌株(P1、P2、P3和P4),从形态学、生理生化特征及16Sr DNA等方面对菌株进行了鉴定,探讨了菌株的最适培养条件,研究了其对鳗草植株存活、生长、生理及根际土壤酶活力的影响。结果表明,菌株P1～P4分别为芽孢杆菌(Bacillus altitudinis P1)、桑肠杆菌(Enterobacter mori P2)、大肠埃希氏菌(Escherichia coli P3)和Cobetia marina P4; 72 h菌株培养液中可溶性磷含量分别为116.98 mg/L、123.13 mg/L、130.21 mg/L和76.54 mg/L;最适培养温度分别为34.67℃、33.95℃、34.60℃和31.19℃;最适培养盐度分别为27.10、28.29、29.54和26.08;最适初始pH分别为8.26、7.92、8.17和8.21。鳗草室外盆栽实验证实,4个接菌处理组对鳗草植株的存活、生长生理及根际土壤酶活力等指标均有不同程度的提高或改善。其中菌株P2对鳗草生长的影响最为显著,单株新叶面积、地上及地下生产力最高,为(54.31±4.79)cm~2、(3.58±0.36)mg/(shoot·d)及(0.28±0.04) mg/(shoot·d),是对照组的2.77、2.91和1.75倍;叶片中叶绿素a、叶绿素b、总叶绿素和类胡萝卜素4种光合色素含量分别为31.35μg/cm~2、12.57μg/cm2、39.42μg/cm~2和6.21μg/cm~2,显著高于对照组(P0.05)。除菌株P4处理组外,其余各处理组的碱性磷酸酶活力均显著高于对照组(P0.05)。但脲酶含量与对照组无显著差异(P0.05)。综合分析认为,桑肠杆菌(Enterobacter mori P2)具备进一步研制溶磷微生物肥料的潜力,在海草床生态系统恢复中可能具有较高的应用价值。研究结果为深入探究高效溶磷菌株功能与代谢调控及其在鳗草植株人工促繁中的作用奠定了基础。     

三氯异氰尿酸对海洋拟阿脑虫种群生长的影响

为探究纤毛虫病原生物海洋拟阿脑虫(Paranophrys marina)在不同浓度三氯异氰尿酸影响下的种群动力学规律,以致病性纤毛虫海洋拟阿脑虫为实验材料,在28℃恒温、光照强度1 000 lx、光暗周期为12∶12(D∶N)的培养条件下,测定其在7个三氯异氰尿酸浓度(0.015、0.030、0.060、0.120、0.250、0.500 mg/L)下种群增长率的变化,并进行不同三氯异氰尿酸浓度(0、0.05、0.15、0.16、0.17、0.18 mg/L)对海洋拟阿脑虫亚急性毒性实验。结果显示,海洋拟阿脑虫种群增长曲线符合逻辑斯蒂增长曲线;三氯异氰尿酸对海洋拟阿脑虫种群增长在经过3 d的停滞期进入增长期,在0.18 mg/L浓度下的繁殖速度最慢;海洋拟阿脑虫在浓度为0.015、0.030、0.060、0.120、0.50 mg/L三氯异氰尿酸下的种群密度峰值分别为4.49×10~4、4.10×10~4、9.09×10~4、3.85×10~4、1.87×10~4个/m L,浓度0.25 mg/L时,没有出现明显的种群密度增长期;三氯异氰尿酸浓度为0.15、0.16、0.17、0.18 mg/L,海洋拟阿脑虫的最大种群密度分别为1.35×10~4、1.23×10~4、9.60×103、9.30×103个/m L,三氯异氰尿酸浓度的增加能有效抑制海洋拟阿脑虫的种群增长。研究表明,0.18 mg/L三氯异氰尿酸能显著抑制海洋拟阿脑虫种群增长率,实验结果可为海洋尾丝虫病的防治提供实验生态学数据。     

大叶藻生殖枝的室内离体培养及种子早期发育研究

对大叶藻不同生长状态的生殖枝进行离体培养,探究室内暂养大叶藻离体生殖枝获取成熟种子的可行性,观察并描述了大叶藻离体生殖枝的开花、传粉、种子成熟、种子萌发、幼苗发育的动态过程以及大叶藻生殖枝、成熟种子、胚的解剖结构。实验结果表明,大叶藻生殖枝的结构对海水环境是高度适应的;花柱的形态变化是大叶藻开花过程的显著特点;大叶藻种子胚的结构较特殊,“U”型子叶包裹胚根、胚芽、胚轴,这导致了其特有的萌发过程;为了不错失种子收集良机,在不了解某地区大叶藻物候特性时,提前采收生殖枝并进行室内培养,是一种获取大叶藻种子的有效方法。     

Effect of habitat fragmentation on spawning migration of brown trout (Salmo trutta L.)

Abstract –  Human-induced habitat alteration is one of the main causes of the decline of freshwater fish populations. The watershed of the River Bidasoa (Spain) is an example of heavily fragmented habitat. The local brown trout ( Salmo trutta L.) population is disturbed, with evidence of poor recruitment as well as low adult densities in the main stem. Forty male and female adult migratory trout were tagged with external or internal radio transmitters and released. Fixed stations with data loggers and mobile antennae were used with daily surveys to track fish movements during the migration and spawning period (3 months). Migration distances did not exceed 10 km, and half of the fish never entered a tributary in the study area. Fragmentation because of weirs on the main stem apparently prevented fish from reaching their spawning destination. Fish that entered the tributaries were first confronted with an accessibility problem because of low discharge. However, each fish chose one tributary, without making attempts to run up in other tributaries. Once in the tributary, fish were restrained in their upstream movements by dams. The study area appeared to be isolated from the vast upper part of the watershed. Within the study area, upper parts of tributaries also seemed strongly disconnected from the main stem. This study illustrates the negative impact of river fragmentation on S. trutta migration pattern. Population sustainability can be directly affected through the low availability of spawning grounds for migratory fish. Long-term effects of fragmentation may cause reproductive isolation within watersheds, which in the case of trout also means isolated phenotypic population units.     

Effect of habitat type on growth and diet of brown trout, Salmo trutta L., in stream enclosures

The effect of habitat on the growth and diet of brown trout, Salmo trutta L., stocked at the same densities in nine stream enclosures, comprising three habitat types of different quality, were tested. The habitats, which were created based on microhabitat preference data, were a shallow water habitat lacking cobbles (habitat 1), a deeper, mixed cobble-bottomed (128-384 mm diameter) habitat (habitat 2) and a large cobble-bottomed (256-384 mm) habitat of intermediate depth (habitat 3). Brown trout were found to have greater increases in total biomass in habitats 2 and 3 than in habitat 1. The pattern for length did not follow that of biomass as trout had greater increases in total length in habitat 2 than in the other two habitats. Biomass of food in trout diets reflected habitat-specific fish biomass changes, with a greater total biomass of prey as well a greater biomass of the leech, Erpobdella, in habitats 2 and 3 than in habitat 1. There were no habitat-specific differences in the biomass of benthic or drifting invertebrates in the enclosures, with the exception of a tendency for an effect of habitat on the biomass of Erpobdella. Although there may have been habitat-specific differences in food resources that were not detected, it is believed that the higher biomass growth in habitats 2 and 3 may have reflected differences in cover afforded by the deeper water and coarser substrates and/or improved foraging opportunities facilitated by the larger volumes of water in the deeper habitats in which the trout could search for prey.     

Reciprocal transplant of the seagrass Zostera marina L. Effect of substrate on growth

The seagrass Zostera marina L. is an important component of the temperate coastal ecosystem making it a candidate for reestablishment and transplantation. In this investigation, the effect of different substrate types on Zostera growth was studied utilizing transplantation of individual short shoots and rhizomes. Data analysis showed that the new leaves produced formed the most reliable parameter for relative production. The results indicate that transplants originating from a natural silt environment displayed best overall growth. Plants grown in a silt substrate continually afforded better growth. The quality of the sediment was also examined. The results indicate that plants grown in undisturbed natural sediments were more successful than plants in sediments which were disturbed. Aspects of the physiology and ecology of Zostera are discussed with reference to the substrate.     

Impact of stocked Atlantic salmon (Salmo salar L.) on habitat use by the wild population

Laffaille P. Impact of stocked Atlantic salmon (Salmo salar L.) on habitat use by the wild population.
Ecology of Freshwater Fish 2011: 20: 67–73. © 2010 John Wiley & Sons A/S Abstract – We investigated the summer habitat occupied by populations of young‐of‐the‐year wild and stocked (farmed populations released into the native range) Atlantic salmon under allopatric and sympatric conditions. Under allopatric conditions, farmed and wild salmon occupied habitats with the same characteristics. The salmon preferentially occupied the riffle areas. However, under sympatric conditions, the fish occupied meso‐ and micro‐habitats with different characteristics. Wild salmon avoided habitats used by farmed salmon and preferred glide areas with considerable vegetation cover. This study suggests that differences in the pattern of habitats used by young Atlantic salmon were both size‐ and origin‐dependent and may result from intra‐species competition between farmed and wild populations. Given that stocking with farmed Atlantic salmon is carried out intensively to enhance recreational angling or to conserve salmon populations, this study warns that this can have a negative impact on the extant wild Atlantic salmon population.     

The structural and histochemical analyses and chemical characters of the cuticle and epidermal walls of cotyledon in ungerminated seeds of <Emphasis Type="Italic">Zostera marina</Emphasis> L.

How Zostera marina L. adapts to environmental stresses is of major interest to researchers wanting to obtain a better understanding of how to preserve this ecologically important seagrass. We have examined the structure and chemical properties of the cuticle and epidermal walls of Z. marina cotyledons at the pre-germination stage by microscopy, histochemistry, and chemical analyses. The epidermal cells, which have a smooth plasma membrane and slight wall-ingrowth, are surrounded by thickened outer tangential walls consisting of cellulose and pectic substances. The thick cuticle layer covers the outer surface of the outer tangential walls; the former were observed here to be much thicker than has been reported earlier for the leaves and sheaths of Z. marina. Chemical analysis of the isolated cuticle by attenuated total reflectance–infrared Fourier transform spectrometry and gas chromatography–mass spectrometry detected C₁₆ and C₁₈ fatty acids, ω-hydroxy fatty acids and β-sitosterol as components of the wax and cutin. The outermost cuticle layer was also observed to be covered with a slimy layer consisting of some polysaccharides. These results suggest that the extremely thick cuticle and slimy layer could play a significant role in protecting the cotyledons from environmental stresses at the pre-emergence stage and just after emergence.     

The utility of simple fish community metrics for evaluating the relative influence of fishing vs. other environmental drivers on Caribbean reef fish communities

Fish community metrics have been extensively investigated as indicators of fishing effects for ecosystem‐based fisheries management (EBFM) in temperate systems. Little similar work has been performed in the coral reefs of the Caribbean, where simple indicators are urgently needed. Here, we use 415 coral reef surveys throughout the Caribbean to assess the potential of four simple and intuitive fish community metrics, namely, fish biomass, fish density, average fish weight and species richness, to separate fishing effects from those of other environmental factors at both local (tens of kilometres) and broad (hundreds to thousands of kilometres) spatial scales. We found that these fish metrics differed considerably in environmental correlates and the spatial scales underlying fish metric–environment associations. Average fish weight and fish biomass were most sensitive to fishing indices at both spatial scales, although average fish weight responded more sensitively and specifically to fishing than fish biomass. Fish density and species richness were most sensitive to temperature over broad scales and to macroalgae and relief height over local ones. All fish metrics were negatively correlated with macroalgae over broad scales, supporting the utility of macroalgae to inform about the integrity of entire reef ecosystems. Most of the fish metric variance associated with fishing pressure operated over broad scales, highlighting the need for a Caribbean‐wide view of fish community status to establish local management objectives and avoid shifting baselines. Our study clarifies the utility of simple fish community metrics as indicators of fishing effects for EBFM in the Caribbean.