Recruitment Patterns of Juvenile Fish at an Artificial Reef Area in the Gulf of Mexico

Rachel N Arney,Catheline Y M Froehlich,Richard J Kline

doi:10.1080/19425120.2016.1265031

Abstract

AbstractIn 2011 the Texas Parks and Wildlife Department and the Coastal Conservation Association of Texas deployed over 4,000 concrete culverts in a designated artificial reef area off Port Mansfield, Texas, to enhance habitat for sport fish species in the Gulf of Mexico. A study was conducted to assess juvenile fish recruitment at varying culvert densities within the artificial reef area. Standard monitoring units for the recruitment of reef fish (SMURFs) were used to sample juvenile fish, and these collections were compared with visual scuba surveys. The 0.027‐m3 SMURFs were placed at four different culvert densities (0, 1–50, 51–100, and 101+ culverts in a 30‐m radius) and sampled during 2013 to 2014. Measurements of rugosity, vertical relief, and percent cover were collected to elucidate factors that drive juvenile recruitment. Average species richness was highest at sites with no culverts and lowest at dense culvert sites. Species compositions were significantly different between sampling locations with no culverts and all locations with culverts; average similarity was 33.8%. Belted Sandfish Serranus subligarius was the most ubiquitous species among all sampling locations. Visual scuba surveys at the same locations showed lower diversity indices of the juvenile fish community than observed by SMURFs and were only 14% similar to the community sampled by the SMURFs. These findings suggest SMURFs are a more effective tool for examining juvenile fish at an artificial reef due to the cryptic nature of juveniles and the low visibility around shallow reefs. Additionally, commercially important Yellowedge Grouper Hyporthodus flavolimbatus, Warsaw Grouper H. nigritus, and Red Snapper Lutjanus campechanus juveniles were only found at SMURFs at sampling locations with no culverts. The presence of juveniles of these key species suggest that fisheries management may benefit from creating low‐relief reef patches away from the main reef where juvenile fish can recruit and grow.

Highlights

Artificial Reef Use and HistoryArtificial reefs are used throughout the world’s oceans as marine habitat enhancement and as a mitigation tool to augment exploited fish populations lost to anthropogenic effects (Alevizon and Gorham, 1989; Bohnsack and Sutherland, 1985; Carr and Hixon, 1997; Pickering and Whitmarsh, 1997)
Because H. aurolineatum arrived in heavy pulses only in June and July 2013/2014, they were excluded from certain analyses (Table 3)
Juvenile fish populations at the South Padre Island artificial reef recruited differently depending on sampling station configuration

Summary

Introduction

Artificial Reef Use and HistoryArtificial reefs are used throughout the world’s oceans as marine habitat enhancement and as a mitigation tool to augment exploited fish populations lost to anthropogenic effects (Alevizon and Gorham, 1989; Bohnsack and Sutherland, 1985; Carr and Hixon, 1997; Pickering and Whitmarsh, 1997). Overfishing and harmful fishing practices (Edinger et al, 1998), increased coastal development (Shahidul Islam and Tanaka, 2004), agricultural runoff (Fabricius, 2005), harmful tourist activities (Van Treeck and Schuhmacher, 1998), and rising sea surface temperatures (Baker et al, 2008) are common stressors on natural coral reefs and fish populations. Both natural and artificial reefs can aggregate reef fish species by boosting natural biological resources to which the fish and other marine organisms are attracted (Bohnsack and Sutherland, 1985). An increase in available shelter can potentially increase juvenile fish populations and overall fish abundances (Ambrose and Swarbrick, 1989; Alevizon and Gorham, 1989; G. Rilov and Benayahu, 2000), Well-managed artificial reefs are intended to preserve, manage, and increase exploited fish populations (Gallaway, Szedlmayer, and Gazey, 2009)

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