What is the impact on fish recruitment of anthropogenic physical and structural habitat change in shallow nearshore areas in temperate systems? A systematic review protocol

Biljana Macura,Lars Rudstam,Britas Klemens Eriksson,Laura Airoldi,Oona M Lönnstedt,Pär Byström,Josianne Støttrup

doi:10.1186/s13750-016-0061-z

Abstract

Abstract Background Shallow nearshore marine ecosystems are changing at an increasing rate due to a range of human activities such as urbanisation and commercial development. The growing numbers of constructions and other physical and structural alterations of the shoreline often take place in nursery and spawning habitats of many fish and other aquatic species. Several coastal fish populations have seen marked declines in abundance and diversity during the past two decades. A systematic review on the topic would clarify if anthropogenic physical and structural changes of near-shore areas have effects on fish recruitment and which these effects are. Methods The review will examine how various physical and structural anthropogenic changes of nearshore fish habitats affect fish recruitment. Relevant studies include small- and large-scale field studies in marine and brackish systems or large lakes in temperate regions of the Northern and Southern hemispheres. Relevant studies may be based on comparisons between undisturbed and disturbed areas, before and after disturbance, or both. Relevant outcomes include measures of recruitment defined as abundance of juveniles of nearshore fish communities. Searches will be made for peer-reviewed and grey literature in English, Dutch, Danish, Finnish, German, Swedish and Spanish. All fish species and species groups will be considered in this review. Included relevant studies will be subject to a critical appraisal that will assess study validity. From relevant included studies, we will extract information on study characteristics, measured outcomes, exposure, comparators, effect modifiers and critical appraisal. Data synthesis will contain narrative and summary findings of each included study of sufficient quality. Meta-analysis may be possible in cases where studies report similar types of outcomes.

Highlights

Shallow nearshore marine ecosystems are changing at an increasing rate due to a range of human activities such as urbanisation and commercial development
Many coastal populations of fish have seen marked declines during the past two decades [15,16,17,18,19]. These declines have been linked to a number of factors including overexploitation, but it is becoming increasingly evident that the problem of declining abundances appears to be caused by factors affecting the early life stages of many species [11, 20]
Controversies remain as to what the primary causes of larval and juvenile fish declines are; whether anthropogenic alteration or loss of nursery coastal habitats are responsible for the declines; to what extent various habitat restoration approaches are effective; and what, if anything, can be done to reverse the declines of fish stocks [5, 12]

Summary

Methods

Search terms The following English language search terms will be used: Population terms: shore*, bay*, coast*, estuar*, lagoon*, lake*, intertid*, nears$hore, shallow, seagrass*, seaweed*, wetland*, marina*, floodplain*, fiord*, mudflat*, saltmarsh*, eelgrass*, “biogenic habitat*”, “habitat-forming specie*”, “kelp forest*”, “mussel bed*”, “oyster bed*”, “Sabellaria bed*”, “sand bank*”, “shellfish habitat*”, littoral, marsh*, macrophyt*, “maerl bed*”, “habitat-engineer* species”, “canopy-forming alga*”, “fucoid alga*”. Members of the review team may use their contacts to find relevant grey literature on the topic, including non-English publications (in Dutch, Danish, Finnish, German, Swedish and Spanish). Studies that evaluate the effects of non-structural changes of the habitat, such as change of temperature or chemical structure of the aquatic system (including effects of pollution, toxicity, eutrophication or oxygen depletion), conservation policy interventions (e.g. the effects of marine protected areas), or the effects of climate change and rising sea levels on the fish stocks and do not include any measure of structural or physical habitat modifications will be excluded from this review. We will extract information on study characteristics, data on measured outcomes, exposure details, comparators, effect modifiers and critical appraisal. This list may be expanded during the review process depending on the type and variety of included studies.

Background

Findings