A preliminary assessment of larval fish assemblages on artificial reefs in the nearshore Southern Brazil

Abstract

Artificial reefs (ARs) have been deployed on the inner shelf of Paraná, Southeast Brazil, as protection against destructive trawling activities, and to offer habitat for local fauna for recovery of biodiversity. The purpose of this study was to develop a preliminary characterization of the ichthyoplankton community associated with both artificial and natural reefs in the Currais Archipelago, and perform a comparison of fish larvae composition between ARs and nearby unconsolidated substrate. Two sampling methods were used, light traps and a plankton net. A total of 12 families and 14 species were identified, expanding the total species list in the area by eight species and three families. Differences among assemblages on ARs and unconsolidated substrate indicate that ARs seem to be effective attractors to fish larvae. Particular attention is drawn in regard to the "attractor effect" for exotic species that do not naturally reside in the area, such as Omobranchus punctatus. The large abundance of fish eggs on ARs suggests that these artificial structures can improve local production. These results are the first step needed to better define guidelines for sustainable use and management of ARs and Currais Archipelago, a Marine National Park.

Assessing the Conservation Value of Artificial and Natural Reefs via Ichthyoplankton Spatio-Temporal Dynamics

“…The differences suggest that the natural reefs in the ESA may serve as breeding grounds for species of the families Scaridae, Labridae, and Mugilidae, whereas the ARs may serve as breeding grounds for the families Lutjanidae, Synodontidae, Carangidae, Fistularidae, and Haemulidae, which indicates the potential of these novel habitats to expand spawning grounds and fish production in the Espiritu Santo Archipelago. This further contribution of the ARs could benefit adjacent fishing grounds through connectivity via the export of eggs and larvae (recruitment subsidies) [55,56], a phenomenon recorded in other artificial reefs around the world [23,57,58]. In addition, the present study highlights the potential attraction effect of artificial reefs on fish larvae, with special attention being paid to mesopelagic species like Benthosema panamense and pelagic species like Cetengraulis mysticetus and Hemiramphus saltator, which do not tend to naturally reside in reef areas.…”

“…Since the reproductive activities of fish determine the presence and distribution of their early developmental stages [16,53,54], the predominance of the egg stage (mainly early development) and yolk sac larvae in the ichthyoplankton samples implies that the studied reefs may serve as spawning grounds for various reef species [21][22][23][24][25]. Although the dominant ichthyoplankton species in both the natural and artificial reefs were nearly identical, supporting the hypothesis that a mimicking of fish communities may occur when artificial reefs are closer to natural reefs [40], the ichthyoplankton community assemblages varied at the species level.…”

Marine artificial reef (MAR) interference in artisanal fisheries in Brazil: use of traditional knowledge

“…In Brazil, the use of MARs is recent, but it is increasing due to the participation of research institutions and nongovernmental organizations (NGOs), with the help of environmental agencies for their implementation (Costa et al, 2014). Currently, there are several MARs along the Brazilian coast in the states of Bahia (12°52'S -38°45'W), Rio de Janeiro (22°54'S -43°12'W) and Paraná (25°30'S -48°30'W) (Lima et al, 2018;2020;Alegretti et al, 2021). They allow biomass to increase, benefiting artisanal fisheries, and create obstacles to eliminate trawling in coastal areas.…”