Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—Multiple coastal development activities coupled with unsustainable management have caused environmental degradation in the Santa Marta region of Colombia. To mitigate this impact, Ecopetrol entered into alliances with private and government institutions to initiate an integrative artificial reef project in Pozos Colorados Bay. To develop the project’s framework, it was necessary to (1) establish context and objectives, (2) design plans and reef construction, (3) strengthen a target social population, and (4) conduct pre- and postdeployment ecological assessments. The achievement of each objective was met with delays and constraints, mainly due to administrative issues and legal requirements. Nevertheless, interventions and interactions among representatives of the 10 institutions involved in the project, as well as the strong commitment of fishers from three organizations in all stages of the process, were indicators of project’s success. Together, these actions and contributions resulted in the deployment of the first six artificial reefs in a 137-ha area. Moreover, recorded changes in biological assemblages before and after reef deployment (richness: 3–37 species; abundance: 30.3–1,615.7 individuals), along with the presence of commercial, ecological, and endangered important species, support the concept of habitat enhancement procedures used here as a strategy for biodiversity conservation with potential for ecotourism activities. The utilization of this technology should be conducted in compliance with concerted schemes for coastal resource management and precautionary principles, directed towards the conformation of discrete marine reserves as future models of sustainable production in sensitive areas.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—The subtidal rocky reefs that surround the Palos Verdes Peninsula in Los Angeles County, California, USA are subject to multiple anthropogenic impacts, including many (at least partially) human-induced landslides over the past half century, which have resulted in chronic sedimentation (e.g., reef burial and scour) and associated turbidity effects along a major stretch of this coastline. The amount of rocky reef habitat has significantly decreased; as such, determining the optimum technique for restoring this lost habitat is the focus of this study. Over the past decade, we mapped and intensively surveyed the nearshore physical and biological characteristics both inside this impacted area and in surrounding reference areas that contain extensive rocky reef habitat with established kelp forests. Notable among all survey locations is a relatively high-relief (~5 m) area of reef within the sediment impacted area that consistently has the highest fish biomass density among anywhere on the peninsula. The high structural relief prevents sediment accumulation, scour, and subsequent reef burial, and this reef ultimately served as the example for the design of sets of quarry rock reef “blocks” that together form the proposed restoration reef. Our primary objective was to use the 63,500 metric tons of quarry rock the budget would allow us to create the most productive habitat by restoring the natural reef environment while balancing scientific study design considerations (i.e., replicated reef components at multiple spatial scales) with maximizing the potential for an effective restoration effort across the range of important species and overall kelp forest biodiversity. To meet this objective, we considered multiple criteria that incorporated engineering specifications and biological performance and were informed by the scientific literature and results of natural and artificial reef surveys in this region. Ultimately, the design incorporated heterogeneity at multiple spatial scales while attempting to maximize high relief components, surface area to volume ratio, perimeter, ecotones, and small-scale current flow features and nutrient flux and while being consistent with the size of natural reefs along the Palos Verdes Peninsula. Further, placement and spacing of individual reef blocks (i.e., 2 × 48 m heterogeneous quarry rock reefs) included space for sand channels between blocks to permit sediment transport and create sand/rock ecotone habitats while remaining close enough to each other and existing natural reefs to maintain biological connectivity. Reef blocks were also located at the depth (15–20 m) where the most productive reef habitat in the region was observed. Finally, we discuss a proposed pre- and post-construction monitoring program and additional studies that could be performed that would leverage the replicated elements in the restoration reef design to inform future reef restoration programs.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—Reef-fish assemblage structure was compared among multiple artificial and geologic (i.e., naturally occurring hard bottom) habitats in the northeastern Gulf of Mexico during 2014–2016 as part of a larger fishery-independent survey. Baited remote underwater video systems equipped with stereo cameras were deployed (<em>n </em>= 348) on 11 habitat types, classified through interpretation of side-scan sonar imagery. In the video samples, 11,801 fish were enumerated. Nonparametric analysis of reef-fish assemblages detected four clusters related to habitat; assemblages associated with geologic habitats were distinct, whereas the remaining three clusters represented groupings of artificial habitats of different size, scale, and complexity. While many species, including Vermilion Snapper <em>Rhomboplites aurorubens </em>and Red Snapper <em>Lutjanus campechanus</em>, were observed in greater numbers on artificial reef habitats, most species were observed in all habitats sampled. Among artificial reef habitats, the habitat cluster consisting of unidentified depressions, unidentified artificial reefs, construction materials, and reef modules was similar to geologic habitats in supporting larger individuals, specifically Gray Triggerfish <em>Balistes capriscus </em>and Red Snapper. In contrast, the habitat cluster consisting of smaller, generally solitary chicken-transport cages was inhabited by smaller individuals, including smaller Red Snapper. Although geologic reefs are the predominant reef habitat throughout much of the eastern Gulf, artificial reefs are important locally, especially in the Florida Panhandle. Accordingly, continued incorporation of artificial reef habitats within large-scale fishery-independent monitoring efforts is critical to the accurate assessment of the status of reef-fish stocks on broad spatial scales.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—This paper focuses on interactions between reefs, fisheries, and their management and discusses the relationship between reef fish and their habitat. Hard bottom is much less extensive than fine sediments on most continental shelves but supports epifauna/flora as cover for reef fish and serves as habitat for their prey species. Corals, epifauna, and macroflora on natural reefs function as feeding, shelter, and aggregation sites and often have fractal characteristics. Size frequencies of catches from unfished banks may reflect the aggregate of crevice size spectra present, and this influences growth and natural mortality rates at size. It is suggested that migration is initiated when juvenile fish outgrow cover in nursery areas, which only offered predator protection at smaller sizes. Juveniles are then forced to move further offshore where cover for protecting larger reef fishes is often more available. Large cavities are rare on most natural outcrops or reefs, but these attract large fish and artificial reefs are often designed to have large cavities needed by mature reef fishes. Once artificial reefs are located by fishermen, large, resident fishes are readily captured. Unless some offshore reefs or refugia are protected, spawning potential could be affected.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—Research and development (R&D) on the design and construction of artificial reefs in Malaysia was initiated by researchers from the Fisheries Research Institute, Department of Fisheries Malaysia (DoFM) based in Penang in 1975. Initially, R&D only focused on simple designs and construction using discarded tires, wooden fishing boats, polyvinyl chloride (PVC) pipe, reinforced concrete, and ceramic sewerage pipe. These reefs were used in fisheries management to maximize resource enhancement, resource conservation, and habitat rehabilitation and mitigation, as well as being an aid to alleviate the problem of depleting fish resources in coastal waters. However, in 2006, the DoFM made a major policy change in the design and construction materials of artificial reefs in the country. The focus was to construct large, heavy, and robust artificial reefs using durable materials such as reinforced concrete and steel to deter the encroachment of destructive fishing gears, especially trawlers, along the coastal and in marine protected areas. These new artificial reefs addressed several issues, such as fish behavior, target species, physical oceanography, and marine engineering, in their design. The reinforced concrete artificial reefs were built according to the British Standard 8110 under the supervision of officers from the Engineering Division and Research Division of the DoFM. Presently, the DoFM has designed 21 types of artificial reefs that have been deployed at 130 selected locations in Malaysia. This paper reviews the progress of R&D on the design and construction of artificial reefs using tires, wooden fishing boats, reinforced concrete, PVC pipe, ceramic materials, and steel in Malaysia between 1975 and 2017.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—Twenty artificial reefs were deployed early in October 2005 approximately 20 km south of Dauphin Island, Alabama (USA), in the Hugh Swingle General Permit Area. Each reef consisted of 12 concrete blocks (20 cm long × 20 cm wide × 41 cm high) arranged on a plywood base (1.5 m² )and deployed on the bottom, 20 m deep. To quantify the epibenthic assemblage on the reefs, four removable bricks were attached to the reefs. Ten reefs were coated with copper-based, anti-fouling paint and 10 reefs were unpainted. Fish and epibenthic assemblages were compared between reef treatments (i.e., with and without copper-based paint). Reefs were surveyed 1 week after deployment in October 2005, then again in December 2005, May 2006, August 2006, and December 2006. During each survey, two scuba divers visually estimated the densities of all fish species and removed one of the removable bricks to identify and quantify the epibenthic organisms. The epibenthos (coverage area, biomass, diversity, species richness) and fish assemblages (total fish density, species diversity, species richness) were greater on unpainted reefs. Red Snapper <em>Lutjanus campechanus</em>, wrasses <em>Halichoeres </em>spp., Bank Sea Bass <em>Centropristis ocyurus</em>, and Atlantic Spadefish <em>Chaetodipterus faber </em>had higher densities on unpainted reefs. This study indicated that recruitment of fishes to artificial reefs was not just attraction to structure, but that growth of epibenthic assemblages had a significant influence on recruitment.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—In recent years, as reported by the Malaysian Department of Fisheries, the decline in demersal fish resources is due to excessive exploitation. This indicates that management and protection of these resources and their habitat are required. <em>Teranas </em>is identified as important critical marine habitat and locally in Malay is defined as a hard rock substrate on the seabed. Teranas can appear in all shapes and sizes, depths, and locations. The combination of these various bottom features often make a teranas attractive to fish. The objective of this study is to detect a teranas so that it can be located and managed through mapping. Sonar in the form of a multibeam echosounder was used to map a teranas with a combination of bathymetry and water column features to identify the signature for teranas. The result produced a signature library to readily identify a teranas with the multibeam echosounder. An important factor in determining the signature for the teranas was the seabed structure and its associated marine life. Bathymetry identified the seabed structure, and the water column characteristics helped verify the presence of marine life. Fishing and visual surveys with scuba diving were also conducted to verify the effectiveness of the multibeam echosounder to identify the teranas. These study results can be used as an aid for planning and managing a teranas to help sustain the associated fisheries resources. Moreover, since a teranas is similar in structure and position to an artificial reef, the multibeam echosounder, when coupled with visual diver-based surveys and fishing effort, could be used to identify the extent and marine fauna associated with an artificial reef. This research will help in providing strategic location selection for artificial reef placement.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—The Wheeler North Reef (WNR) is a large (70.4 ha [174 acre]) artificial reef in Southern California designed to mitigate the loss of kelp forest habitat and its associated community of algae, invertebrates, and fishes caused by the operation of the San Onofre Nuclear Generating Station (SONGS). Conditions of the SONGS’ operating permit require that the success of WNR in compensating for the kelp forest resources destroyed by the 30 years of the power plant’s operations be determined by long-term monitoring that is independent of the owners of SONGS. Performance standards pertaining to physical and ecological attributes of WNR are used as a basis for determining the success of WNR in meeting the mitigation objective to replace kelp forest resources in kind. We discuss details of the sampling design, evaluation criteria, and monitoring results and show how they are used to inform adaptive management that helps to ensure that the mitigation goals are met.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—Artificial reefs in the northwest Gulf of Mexico act as preferential habitat for Gray Triggerfish <em>Balistes capriscus </em>(Gmelin, 1789) and are heavily targeted by local and international fishing efforts. Three artificial reefs off the south Texas coast were studied to investigate the reproductive characteristics of this ubiquitous reef member whose importance to both commercial and recreational fishing has resulted in a dramatic reduction in Gulf of Mexico-wide estimated biomass for the past 20 years. Characteristics examined included sex ratio, peak spawning season, batch fecundity of females (1 × 10⁶ oocytes), fork length (FL, mm) at maturity, and batch fecundity as a function of FL or weight (i.e., Δ1 × 10⁶ oocytes = ΔFL). These characteristics were investigated to build a foundational understanding of an understudied region of the Gulf and a relatively new artificial reef habitat. Reef sites managed by the Texas Parks and Wildlife Department Artificial Reef Program were sampled for 1 year, yielding 112 individuals. The sex ratio was 1:1 males to females but varied among sample sites, suggesting that an unidentified factor may have influenced aggregations of males and females. Spawning season was similar in other regions of the Gulf of Mexico (i.e., between June and August with a peak in July). Female batch fecundity was 7.36 × 10⁵ ± 2.69 × 10⁵ mature oocytes, and the batch fecundity to FL relationship was 14.353 × FL^1.88, similar to other populations of Gray Triggerfish in the Gulf of Mexico.