珠江口大型底栖生物群落生态特征

2006年夏季和冬季分别对珠江口附近海域进行了大型底栖生物调查.调查共鉴定出大型底栖生物245种,多毛类最多(140 种).其中夏季共获大型底栖生物153种,多毛类最多(91种);冬季共获大型底栖生物157 种,多毛类最多(93种).夏冬季调查都有出现的生物种类65种.夏季珠江口大型底栖生物平均生物量为14.313 g/m2,平均丰度为205.3 ind/m2.冬季珠江口大型底栖生物平均生物量为13.077 g/m2,平均丰度为168.8 ind/m2.大型底栖生物种类数、生物量和丰度均呈现由河口内向外海增加的趋势.根据Bray-Curtis相似性系数矩阵数据对调查区域的大型底栖生物群落做了聚类(CLUSTER)和多维排序尺度(MDS)分析.结果显示,夏季可以划分为3类生物群落,冬季可以划分为5类生物群落.群落生物多样性分析结果显示,夏季珠江口北部和中部比南部生物多样性低;冬季珠江口北部生物多样性最低.利用丰度生物量比较曲线分析了大型底栖生物群落受干扰程度.结果表明,夏季大型底栖生物群落未受到干扰;冬季珠江口最北部生物群落Ⅰ处于中等干扰程度,其它生物群落未受干扰或受轻微干扰.海区大型底栖生物分布受珠江冲淡水的影响较为明显.     

我国海洋大型底栖生物多样性研究及展望:以黄海为例

本文综述了我国海洋大型底栖生物生态学和生物多样性研究进展,指出在该领域已有的研究中以胶州湾、长江口、福建和浙江沿岸等海域研究较多,其他海域还需要加强.介绍了常规大型底栖生物群落研究(包括种类组成、栖息密度(丰度)、生物量、生物多样性、次级生产力、能量级等)中的研究方法,环境变化、环境污染、海洋工程建设等对大型底栖生物的影响等方面的主要研究成果和进展,并重点以黄海为例,列举了已有的主要调查项目和研究成果.我国已有的研究表明,渤海海域底栖动物区系简单,大型底栖生物共413种,种数在四个海区中最少,优势种主要是低温、广盐暖水种;年总平均生物量为19.83 g/m2,以软体动物占有绝对优势;年总平均栖息密度474个/m2,多毛类和软体动物为主要贡献类群.黄海大型底栖生物共853种,优势种为狭盐性北温带种;北黄海年总平均生物量为99.66 g/m2,以棘皮动物最高;南黄海年总平均生物量为27.69 g/m2,多毛类贡献量最高;北黄海年总平均密度为2,017.40个/m2,而南黄海只有88.67个/m2差异较大;北黄海大型底栖生物的总平均密度和生物量远高于其他海域.南黄海年平均次级生产力为4.98 g(去灰干重)/m2,两个高生产力区位于黄海冷水团两侧.东海共发现大型底栖生物l,300种,主要优势种类有45种,与黄海优势种生物之间有很大差别;东海平均生物量的季节变化不显著,基本趋势为春季＞冬季＞夏季＞秋季;东海各海域的年总平均生物量浙江海域(28.22 g/m2)＞长江口海域(15.55 g/m2)＞台湾海峡(8.98 g/m2);年总平均栖息密度为164个/m2,呈现由北向南逐渐增加的趋势.南海大型底栖生物共发现1,661种,明显高于渤、黄、东海,部分优势种类与东海相同,与黄海、渤海差别较大;年总平均生物量为20.06 g/m2,基本趋势为春季＞冬季＞秋季＞夏季,软体动物和棘皮动物为主要贡献类群;年总平均栖息密度为198个/m2,夏季＞春季＞冬季＞秋季,多毛类生物为主要贡献者.指出随着人类活动和全球气候变化对海洋环境的影响越来越剧烈,对海洋生物资源和生物多样性的保护显得尤为急迫,而对海洋大型底栖生物长期的变化规律、变化机理、未来变化趋势预测的研究,是探究海洋大型底栖生物生态服务功能,提出资源有效保护和合理开发建议,使之永续利用的基础和迫切任务.     

乐清湾大型底栖生物群落特征及其对水产养殖的响应

乐清湾大型底栖生物的四季采样研究。发现124种大型底栖生物,其中多毛类41种、软体动物37种、甲壳类22种、棘皮动物10种和其他类14种。乐清湾大型底栖生物年均生物量41．95g·m^-2年均密度85个·m^-2,生物量棘皮动物居首（约占60％）;密度软体动物最大（约占35％）。生物量和密度分布春季为最高。对乐清湾大型底栖生物分布现状与以往资料及邻近海湾进行了比较,并将大型底栖生物群落对乐清湾牡蛎养殖和网箱养殖的响应做了分析探讨。     

UK~(37)沉积地层记录:三门湾海表温度(SST)和EI Nio现象及其对大型底栖动物生命活动的影响

应用UK37估算三门湾(1916~2003年)表层海水温度,SST波动范围在15.97~18.00℃之间,年平均为17.03℃,此计算值比当年实测海水全年平均温度低3.52℃,与秋季海水实测温度相接近。研究显示出,三门湾的EI Nio事件在大尺度上与东太平洋一样,均受制于气候影响因素,但在变化尺度上又受到地理位置和地方性气候(季风)的影响,事件在形式和年代上相互对应,但其颤动幅度远不如东太平洋强烈。同时通过比较EI Nio期间(2003/2002)和非EI Nio期间(2006/2005)大型底栖生物的群落结构变动信号、生物量、栖息密度以及物种多样性等,研究显示出三门湾若干大型底栖生物对EI Nio事件产生响应迹象,若干大型底栖生物对EI Ni o的响应主要是通过海洋环流的影响来体现生命和生态效应的,主要表现在改变了底栖生物种类数和多样性、以及生命活动及栖息密度分布模式。在EI Nio影响下,台湾暖流入侵势力加强,2003/2002年底栖生物群落种类数减少与海流入侵及盐度密切相关;通过与同海域浮游动物对比研究,三门湾海域浮游动物和底栖生物对EI Nio的生态响应均较大,前者可能与三门湾海域水域较浅,外海暖水从底部入侵改变水温和盐度,直接影响底栖生物的生态环境,致使种类数大大减少有关;而后者由于入侵暖水强度增大,携带大量暖水性浮游动物,呈现出在EI Nio时期浮游动物种类数、生物量和丰度有偏高趋势。     

UK37沉积地层记录:三门湾海表温度(SST)和EI Ni(n)o现象及其对大型底栖动物生命活动的影响

应用U^K37估算三门湾（1916～2003年）表层海水温度,SST波动范围在15．97～18．00℃之间,年平均为17．03℃,此计算值比当年实测海水全年平均温度低3．52℃,与秋季海水实测温度相接近。研究显示出,三门湾的EINino事件在大尺度上与东太平洋一样,均受制于气候影响因素,但在变化尺度上又受到地理位置和地方性气候（季风）的影响,事件在形式和年代上相互对应,但其颤动幅度远不如东太平洋强烈。同时通过比较EINino期间（2003／2002）和非EINino期间（2006／2005）大型底栖生物的群落结构变动信号、生物量、栖息密度以及物种多样性等,研究显示出三门湾若干大型底栖生物对EINino事件产生响应迹象,若干大型底栖生物对EINino的响应主要是通过海洋环流的影响来体现生命和生态效应的,主要表现在改变了底栖生物种类数和多样性、以及生命活动及栖息密度分布模式。在EINino影响下,台湾暖流人侵势力加强,2003／2002年底栖生物群落种类数减少与海流人侵及盐度密切相关;通过与同海域浮游动物对比研究,三门湾海域浮游动物和底栖生物对EINino的生态响应均较大,前者可能与三门湾海域水域较浅,外海暖水从底部人侵改变水温和盐度,直接影响底栖生物的生态环境,致使种类数大大减少有关;而后者由于人侵暖水强度增大,携带大量暖水性浮游动物,呈现出在EINino时期浮游动物种类数、生物量和丰度有偏高趋势。     

风力发电对鸟类的影响以及应对措施

风能是一种清洁而稳定的可再生能源,风力发电可以减少全球温室气体排放,在减缓气候变化中发挥重要作用。然而,风电场的建设会对自然保护、生态环境和动物生存会造成一定的负面影响,其中对鸟类的影响尤为突出。本文通过查阅欧美等国风电场对鸟类及野生动物影响的研究文献,总结了风电场对鸟类的生存、迁徙和栖息地环境的影响,以及导致鸟类与风电塔相撞的影响因素,并提出了相关防范措施和方法。近十年中国风力发电事业发展迅猛,已经成为世界上风电装机容量最大的国家,但中国在评估风电场发展对野生动物影响方面的研究工作非常匮乏。目前,我国应借鉴国外相关研究管理经验,通过长期的连续观测,认真评估国内正在运行和在建风电场对于鸟类和其他野生动物的影响及潜在威胁。同时,应重视鸟类迁徙的基础研究,为新建风电场选址提供科学方案,保证风力发电与生态环境保护之间的和谐发展。     

UK37沉积地层记录：三门湾海表温度(SST)和EI Niño现象及其对大型底栖动物生命活动的影响

应用U K37估算三门湾（1916～2003年）表层海水温度,SST波动范围在15.97～18.00℃之间,年平均为17.03℃,此计算值比当年实测海水全年平均温度低3.52℃,与秋季海水实测温度相接近。研究显示出,三门湾的EI Nio事件在大尺度上与东太平洋一样,均受制于气候影响因素,但在变化尺度上又受到地理位置和地方性气候(季风)的影响,事件在形式和年代上相互对应,但其颤动幅度远不如东太平洋强烈。同时通过比较EI Nio期间（2003/2002）和非EI Nio期间（2006/2005）大型底栖生物的群落结构变动信号、生物量、栖息密度以及物种多样性等,研究显示出三门湾若干大型底栖生物对EI Nio事件产生响应迹象,若干大型底栖生物对EI Nio的响应主要是通过海洋环流的影响来体现生命和生态效应的,主要表现在改变了底栖生物种类数和多样性、以及生命活动及栖息密度分布模式。在EI Nio影响下,台湾暖流入侵势力加强,2003/2002年底栖生物群落种类数减少与海流入侵及盐度密切相关;通过与同海域浮游动物对比研究,三门湾海域浮游动物和底栖生物对EI Nio的生态响应均较大,前者可能与三门湾海域水域较浅,外海暖水从底部入侵改变水温和盐度,直接影响底栖生物的生态环境,致使种类数大大减少有关;而后者由于入侵暖水强度增大,携带大量暖水性浮游动物,呈现出在EI Nio时期浮游动物种类数、生物量和丰度有偏高趋势。     

基于Logistic回归模型的黄河三角洲淡水恢复湿地大型底栖生物种群分布模拟

掌握大型底栖生物种群分布的时空变化对正确把握湿地生态修复效率、揭示湿地生态演替过程具有重要理论与实践意义。选择黄河三角洲地区一千二自然保护区的淡水恢复湿地为研究区,在2014—2015年大型底栖生物野外采样和优势物种的基础上,选择了琥珀刺沙蚕、中华蜾蠃蜚、摇蚊幼虫作为典型优势物种,构建了基于Logistic回归的淡水恢复湿地大型底栖生物种群分布模拟模型。其中,琥珀刺沙蚕和摇蚊幼虫的模拟结果较好,模拟准确率分别为84.9%和77.9%,而中华蜾蠃蜚的模拟结果不甚理想。对比生态补水前后大型底栖生物的模拟分布结果发现,琥珀刺沙蚕主要集中在潮间带区域,且在春、秋两季的生存概率分布差异不显著;而淡水恢复湿地中摇蚊幼虫的分布概率显著提高,其中高于分割值0.5的栖息面积增长了9.9—10.8倍,表明退化湿地生境正处于向淡水湿地演替进程中。     

海上风电磁场对12种海洋生物存活率与行为的影响

海上风电磁场主要由风电场运行中海底电缆产生,其对海洋生物产生的影响目前研究报道较少。为了掌握风电磁场是否对临近海域及养殖环境中的海洋生物产生影响,本研究以如东龙源风电示范区为例,选取江苏近海常见12种海洋生物,通过实验方法研究不同磁场强度(试验Ⅰ:1.00 m T;试验Ⅱ:0 m T、(0.045±0.01)m T、(0.20±0.01)m T、(0.90±0.01)m T、(4.05±0.01)m T、对照(自然地磁场))下,风电磁场对鱼、虾、蟹和贝类的存活、行为等方面的影响。结果表明:当磁场为1.00 m T时,黑鲷存活和行为在短期内(21 d)受磁场影响明显,试验组与对照组存活率差异显著(P0.05),磁场撤销后14 d内无显著性差异(P0.05);试验Ⅱ中,受试生物(黑鲷、半滑舌鳎、文蛤)的存活率仅在(4.05±0.01)m T磁场暴露下的试验组与对照组差异显著(P0.05);受试生物(纵肋织纹螺、半滑舌鳎、天津厚蟹)的行为在(4.05±0.01)m T磁场下试验组与对照组间均存在差异显著(P0.05)。由此可见:短期内(21 d),风电磁场对几种海洋生物的存活、行为有一定的影响,撤销磁场后影响消失。     

长江口及毗邻海域大型底栖动物的空间分布与历史演变

于2005～2006年进行的4个航次调查中,分别对长江口及毗邻海域进行了大型底栖动物取样工作.4个航次共发现大型底栖动物330种,其中包括软体动物122种,多毛类83种,甲壳动物67种,棘皮动物23种,底栖鱼类28种,以及其它类群7种.调查区内大型底栖动物的平均栖息密度为(146.4 ± 22.3)个/m2,平均生物量为(12.8 ± 2.3) g/m2,平均香农指数、丰富度指数与均匀度指数分别为1.72 ± 0.16、1.37 ± 0.19、0.64 ± 0.04.研究表明,调查区内的底栖生物自西向东、由近岸向外海大致可分为3个等级:在最西侧的口内水域与杭州湾,底栖生物种类组成最为单调,生物多样性指数最低,群落结构极为脆弱;在紧邻该底栖生物贫乏带的东侧,也就是口外水域与舟山海区,底栖生物种类组成呈现复杂化,生物多样性指数较高,群落结构显著好于口内水域及杭州湾;在调查海域东南侧的近海区,底栖生物的种类组成最为复杂,生物多样性指数最高,群落结构最为稳定.近半个世纪以来,长江口冲淡水区大型底栖动物的总生物量未出现明显变化,其值在20 g/m2左右变动,但各生态类群的优势地位发生了显著更替.个体较小、生长周期较短的多毛类取代个体较大、生长周期较长的棘皮动物,成为目前冲淡水区最重要的优势类群.     

From fronds to fish: the use of indicators for ecological monitoring in marine benthic ecosystems,with case studies from temperate Western Australia

Ecological indicators are used for monitoring in marine habitats the world over. With the advent of Ecosystem Based Fisheries Management (EBFM), the need for cost effective indicators of environmental impacts and ecosystem condition has intensified. Here, we review the development, utilisation and analysis of indicators for monitoring in marine benthic habitats, and outline important advances made in recent years. We use the unique, speciose benthic system of Western Australia (WA) as a detailed case study, as the development of indicators for EBFM in this region is presently ongoing, and major environmental drivers (e.g. climate change) and fishing practices are currently influencing WA marine systems. As such, the work is biased towards, but not restricted to, indicators that may be important tools for EBFM, such as biodiversity surrogates and indicators of fishing pressure. The review aimed to: (1) provide a concise, up-to-date account of the use of ecological indicators in marine systems; (2) discuss the current, and potential, applications of indicators for ecological monitoring in WA; and (3) highlight priority areas for research and pressing knowledge gaps. We examined indicators derived from benthic primary producers, benthic invertebrates and fish to achieve these goals.     

“海洋生态系统工程师”及其生态作用

“海洋生态系统工程师”是能够塑造栖息地并使其他海洋生物受益的海洋生物种类。海洋中的植物、动物和微生物中均存在为其他生物种类塑造栖息地的“海洋生态系统工程师”,它们的生态作用是其发挥生态功能的基础。本文基于国内外相关文献,系统阐述了“海洋生态系统工程师”生态作用的相关研究进展,并对今后的主要研究方向和内容提出建议。“海洋生态系统工程师”能够在特定的海洋环境中发挥积极作用,但一旦成为入侵种可能会对入侵海域产生负面影响;有些“海洋生态系统工程师”在发挥积极作用的同时也会在不同程度上带来负面影响。今后,应加强海洋生物床、海洋生物礁、海洋生物膜和复合生态系统工程等研究,有效利用“海洋生态系统工程师”的积极作用并防控其负面影响,实现对海洋的综合开发利用和保护。     

气候变化对渔区感知指数、生计策略和生态效应的影响

气候变化已对全球海洋生态环境产生了直接影响,并对渔业资源、渔业生产与渔户生计造成巨大的负面影响,而渔户也通过生计适应影响海洋生态环境。迄今为止,关于渔户对气候变化的感知、生计适应及其生态效应的研究成果较少,基于家庭调查的实证研究更鲜见于报道。选取中国东南沿海的一个典型渔区——福建省霞浦县牙城镇,采用参与式农村评估法(Participatory Rural Appraisal,PRA),基于158份渔户家庭的有效数据,构建气候变化影响感知指数,揭示气候变化影响感知指数与生计资本的内在关联,并进一步探究渔户的生计适应策略及其产生的生态效应。结果表明:(1)渔户对气候变化及其影响的感知较为强烈;(2)渔户的气候变化影响感知指数与生计资本呈现一定的相关性;(3)渔户主要调整了生计生产方式和多样化收入经营两方面策略;(4)渔户生计适应策略的调整会对海洋生态环境产生正面和负面的影响。在此基础上,提出保护渔户生计安全、防范气候变化风险、保护海洋生态环境的政策建议,为当地及其他典型渔区更好地应对气候变化提供有益参考。     

海洋酸化效应对海水鱼类的综合影响评述

人类活动引起的大气CO2浓度的升高,除了使全球温度升高外,导致的另一个严重生态问题——海洋酸化(Ocean acidification,OA),受到社会各界包括科研界的高度重视,该领域的大部分研究结果都是在近十年才发表出来的,目前还有很多需要解决的问题。海洋酸化的研究涉及到很多学科的交叉包括化学、古生物学、生态学、生物地球化学等等。在生物学领域,海洋酸化主要围绕敏感物种,例如由碳酸钙形成贝壳或外骨骼的贝类,珊瑚礁群体等。鱼类作为海洋脊椎动物的代表生物类群,自身具有一定的酸碱平衡调节能力,但相关海洋酸化方向的研究并不是很多。尽管人们对于海洋酸化对鱼类的影响了解甚少,这并不说明海洋酸化对鱼类没有作用或者效应小,在相关研究逐步展开的同时,发现鱼类同样受到海洋酸化的危害,几乎涉及到鱼类整个生活史和几乎大部分生理过程,尤其是早期生活史的高度敏感。因此就目前国内外对此领域研究结果做综述,以期待业界同行能够对海水鱼类这个大的类群引起重视。     

Environmental impacts on the benthic foraminiferal fauna in nearshore ecosystems

This review presents data on how natural and anthropogenic factors affect species composition, abundance, and test morphology of benthic foraminifera of the world oceans. Major emphasis is placed on high sensitivity of foraminifera to changes in the state of the environment, particularly in nearshore zones under anthropogenic impact. It is shown that benthic foraminifera can provide indicators of environmental conditions in marine ecosystems. The effects of mollusk and salmon aquaculture activities on the composition and distribution of foraminifera are considered. It is stressed that a distinction must be made between foraminiferal test morphology variations in response to natural and anthropogenic impacts.     

Application of CART in ecological landscape mapping: Two case studies

The goal of this paper is to introduce a statistical concept to derive ecological classifications of terrestrial and marine environments. Such ecological regionalisations reflect spatial combinations of biotic and abiotic characteristics and therefore may serve for environmental planning and monitoring issues. Referring to two case studies the paper presents how to calculate and map ecological defined regions from geodata by use of decision tree models and GIS-techniques. The first study deals with marine environments, exemplified by benthic habitats in the North Sea. The second study is on an ecological land classification of Europe which was computed using surface data on potential natural vegetation, elevation, soil texture and several climatic elements. Both the marine and the terrestrial ecoregions maps were combined with exposure data provided by environmental monitoring activities. The ecological land classification of Europe was intersected with measurement data on the metal loads in mosses taken from the German part of UN ECE moss surveys. In this way, the temporal development of the metal bioaccumulation within ecoregions since 1990 was assessed. The benthic habitat map was used to regionalise the temporal trend of the temperature conditions near the sea floor for the months of July and January from 1995 to 2000 by analysing these measurements according to the spatial categories of the habitat map. In the future, both ecological regionalisations should be used as a spatial framework for the analysis of up-to-date meteorological and phenological data in order to disclose climate change induced impacts.     

Local human impacts decouple natural biophysical relationships on Pacific coral reefs

Human impacts can homogenize and simplify ecosystems, favoring communities that are no longer naturally coupled with (or reflective of) the background environmental regimes in which they are found. Such a process of biophysical decoupling has been explored little in the marine environment due to a lack of replication across the intact‐to‐degraded ecosystem spectrum. Coral reefs lacking local human impacts provide critical baseline scenarios in which to explore natural biophysical relationships, and provide a template against which to test for their human‐induced decoupling. Using 39 Pacific islands, 24 unpopulated (relatively free from local human impacts) and 15 populated (with local human impacts present), spanning 45° of latitude and 65° of longitude, we ask, what are ‘natural’ biophysical relationships on coral reefs and do we see evidence for their human‐induced decoupling? Estimates of the percent cover of benthic groups were related to multiple physical environmental drivers (sea surface temperature, irradiance, chlorophyll‐a, and wave energy) using mixed‐effects models and island mean condition as the unit of replication. Models across unpopulated islands had high explanatory power, identifying key physical environmental drivers of variations in benthic cover in the absence of local human impacts. These same models performed poorly and lost explanatory power when fitted anew to populated (human impacted) islands; biophysical decoupling was clearly evident. Furthermore, key biophysical relationships at populated islands (i.e. those relationships driving benthic variation across space in conjunction with chronic human impact) bore little resemblance to the baseline scenarios identified from unpopulated islands. Our results highlight the ability of local human impacts to decouple biophysical relationships in the marine environment and fundamentally restructure the natural rules of nature.     

Effects of dredging on critical ecological processes for marine invertebrates,seagrasses and macroalgae,and the potential for management with environmental windows using Western Australia as a case study

Dredging can have significant impacts on benthic marine organisms through mechanisms such as sedimentation and reduction in light availability as a result of increased suspension of sediments. Phototrophic marine organisms and those with limited mobility are particularly at risk from the effects of dredging. The potential impacts of dredging on benthic species depend on biological processes including feeding mechanism, mobility, life history characteristics (LHCs), stage of development and environmental conditions. Environmental windows (EWs) are a management technique in which dredging activities are permitted during specific periods throughout the year; avoiding periods of increased vulnerability for particular organisms in specific locations. In this review we identify these critical ecological processes for temperate and tropical marine benthic organisms; and examine if EWs could be used to mitigate dredging impacts using Western Australia (WA) as a case study. We examined LHCs for a range of marine taxa and identified, where possible, their vulnerability to dredging. Large gaps in knowledge exist for the timing of LHCs for major species of marine invertebrates, seagrasses and macroalgae, increasing uncertainty around their vulnerability to an increase in suspended sediments or light attenuation. We conclude that there is currently insufficient scientific basis to justify the adoption of generic EWs for dredging operations in WA for any group of organisms other than corals and possibly for temperate seagrasses. This is due to; 1) the temporal and spatial variation in the timing of known critical life history stages of different species; and 2) our current level of knowledge and understanding of the critical life history stages and characteristics for most taxa and for most areas being largely inadequate to justify any meaningful EW selection. As such, we suggest that EWs are only considered on a case-by-case basis to protect ecologically or economically important species for which sufficient location-specific information is available, with consideration of probable exposures associated with a given mode of dredging.     

Increasing habitat complexity on seawalls: Investigating large‐ and small‐scale effects on fish assemblages

The construction of artificial structures in the marine environment is increasing globally. Eco‐engineering aims to mitigate the negative ecological impacts of built infrastructure through designing structures to be multifunctional, benefiting both humans and nature. To date, the focus of eco‐engineering has largely been on benefits for benthic invertebrates and algae. Here, the potential effect of eco‐engineered habitats designed for benthic species on fish was investigated. Eco‐engineered habitats (“flowerpots”) were added to an intertidal seawall in Sydney Harbour, Australia. Responses of fish assemblages to the added habitats were quantified at two spatial scales; large (among seawalls) and small (within a seawall). Data were collected during high tide using cameras attached to the seawall to observe pelagic and benthic fish. At the larger spatial scale, herbivores, planktivores, and invertebrate predators were generally more abundant at the seawall with the added flowerpots, although results were temporally variable. At the smaller spatial scale, certain benthic species were more abundant around flowerpots than at the adjacent control areas of seawall, although there was no general pattern of differences in species density and trophic group abundance of pelagic fish between areas of the seawall with or without added habitats. Although we did not find consistent, statistically significant findings throughout our study, the field of research to improve fish habitat within human‐use constraints is promising and important, although it is in its early stages (it is experimental and requires a lot of trial and error). To advance this field, it is important to document when effects were detected, and when they were not, so that others can refine the designs or scale of habitat enhancements or their study approaches (e.g., sampling protocols).