Restoration of Abundance and Dynamics of Coastal Fish and Lobster Within Northern Marine Protected Areas Across Two Decades

Even Moland,Sigurd Heiberg Espeland,Kim Tallaksen Halvorsen,Portia Joy Nillos Kleiven,David Villegas-Ríos,Alf Ring Kleiven,Albert Fernández-Chacón,Susanna Huneide Thorbjørnsen,Mats Huserbråten,Tonje Knutsen Sørdalen,Jan Atle Knutsen,Esben Moland Olsen,Carla Freitas,Halvor Knutsen

doi:10.3389/fmars.2021.674756

Abstract

This article reviews a suite of studies conducted in a network of coastal Marine Protected Areas (MPAs) in Skagerrak, Southeast Norway. In 2006, Norway’s first lobster reserves were implemented, with the aim of protecting European lobster (Homarus gammarus) through a ban on fixed gear. A before–after control-impact paired series (BACIPS) monitoring program was initiated to evaluate effects of protection on depleted lobster populations. Experimental trapping and capture-recapture techniques were combined to track demography of populations, also including movement of individuals within and beyond MPAs and adjacent control areas. Further, population genetics and parentage studies were applied, allowing for estimation of gene flow, and novel work on sexual selection in lobsters. Additional studies have evaluated MPA effects on coastal cod (Gadus morhua), and on commercially harvested labrids (Ctenolabrus rupestrisandSymphodus melops) and anadromous brown trout (Salmo trutta). Together, these studies reported effects of protection pertaining to increased population density, survival, body size and phenotypic diversity, changes in emigration and interaction with surrounding fisheries, and alteration of selection pressure on morphological- and behavioral traits. Designation of MPAs in close collaboration with fishers and managers, long-term monitoring, inclusion of citizen science and evolving research protocols—also including fisheries data—have revealed novel effects of protection and harvesting on marine populations, thus providing substantial contributions to conservation science. Moreover, knowledge of MPA effects on coastal species has impacted harvest regulations showing the utility of MPAs as empirically documented management tools in Norway.

Highlights

Fishing is well established as the driver having had the most impact on biodiversity in marine systems in the past 50 years (IPBES, 2019)
The results indicated that abundance levels increased after protection—albeit highly variable among Marine Protected Areas (MPAs)
Over the course of 16 years since the first before data were collected in designated experimental MPAs in Skagerrak, the network of MPAs described have allowed for substantial contributions to marine- and fisheries conservation science

Summary

Introduction

Fishing is well established as the driver having had the most impact on biodiversity in marine systems in the past 50 years (IPBES, 2019). Marine Protected Areas (MPAs)—areas in the sea that forbid some or all extractive activities are highly useful tools to obtain valuable baseline information on marine populations (Lubchenco et al, 2003; Fenberg et al, 2012; Baskett and Barnett, 2015). Studies conducted in conjunction with the introduction of MPAs have been shown to be useful tools for research and management (Claudet et al, 2008; Babcock et al, 2010; Edgar et al, 2014), e.g., allowing modeling of possible outcomes of different harvest regulations for Atlantic cod Gadus morhua (Fernández-Chacón et al, 2015), and demonstrating benefits of protecting large bodied European lobster Homarus gammarus (Sørdalen et al, 2018)

Methods

Findings

Conclusion