Nearshore marine biodiversity of Osa Peninsula, Costa Rica: Where the ocean meets the rainforest

Abstract

Osa Peninsula in remote southwest Costa Rica harbors 2.5% of global terrestrial biodiversity in only 1,200 km2 and has the largest remaining tract of Pacific lowland wet forest in Mesoamerica. However, little is known about the marine ecosystems of this diverse region. Much of the coastline consists of soft sediment exposed to strong wave action. Three major hard bottom habitat types define this region, including: 1) coral reefs around Isla del Caño Biological Reserve, a no-take marine protected area (MPA) of 52 km2, 2) coastal rocky reefs and islets along the peninsula, including Corcovado National Park, and 3) submerged pinnacles just outside the Isla del Caño MPA. Average coral cover at Isla del Caño was 21%, composed primarily of Porites lobata and Pocillopora elegans. In contrast, coastal rocky reefs were dominated by turf algae (39.8%) and macroalgae (20.7%) with low coral cover (1.1%). Submerged pinnacles were dominated by crustose coralline algae (33.3%) and erect coralline algae (25.7%). Fish assemblage characteristics (species richness, abundance, biomass) were significantly higher at the pinnacles compared to the other habitats and was dominated by schooling species such as Haemulon steindachneri, and the herbivores Kyphosus ocyurus, and Acanthurus xanthopterus. Top predators, primarily Triaenodon obesus, Caranx sexfasciatus, and Lutjanus argentimaculatus, were also most abundant at these pinnacles and accounted for the largest differences in fish trophic structure among habitats. Despite Isla del Caño being fully protected from fishing, biomass was similar to fished areas along the coast and lower than the adjacent submerged pinnacles outside the reserve. Similarly, Corcovado National Park includes 20.3 km2 of no-take MPAs; however, there is limited enforcement, and we noted several instances of fishing within the park. The unique configuration of healthy offshore coral reefs and pinnacles connected to coastal habitats provides corridors for many species including large predators such as sharks and other marine megafauna, which warrants additional protection.

Increasing Forest Cover and Connectivity Both Inside and Outside of Protected Areas in Southwestern Costa Rica

“…The Osa Peninsula is known for its high biodiversity and contains the largest remaining tract of lowland wet forest in Pacific Mesoamerica [29,30]. The peninsula's vegetation consists mostly of tropical wet forest and includes premontane wet and tropical moist forest types [31].…”

Environmental factors modulate the distribution of elasmobranchs in southern Mozambique

“…Coastal reef habitats provide elasmobranch species with refugia, nursery areas, ontogenetic staging points and stable locations for social convergence and reproduction (Wolff et al, 2018;Freeman, 2019;Maioli et al, 2023). Characterizing the mechanisms that underpin elasmobranch species' use of, and relative fidelity to, reef habitat can provide important information for how the habitat could be managed to conserve elasmobranch populations (Friedlander et al, 2022;Hsu et al, 2022;Maioli et al, 2023). Depleted elasmobranch populations across the Indian Ocean, a changing climate, and the worldwide degradation of reefs means that understanding how elasmobranchs use coral reefs is becoming ever more important (Field et al, 2009;Sherman et al, 2023;Simpfendorfer et al, 2023).…”

“…Grey reef sharks (Carcharhinus amblyrhynchos), white tip reef sharks (Triaenodon obesus), zebra sharks (Stegostoma tigrinum), giant manta rays (Mobula birostris), reef manta rays (Mobula alfredi), shortfin devil rays (Mobula kuhlii), Kuhl's mask rays (Neotrygon caeruleopunctata), and blotched fantail stingrays (Taeniurops meyeni) predictably return to specific reef sites to utilize cleaning stations, forage, or reproduce (Pierce et al, 2009;O'Shea et al, 2010;Peñaherrera et al, 2012;Dudgeon et al, 2013;Rohner et al, 2013;Murie et al, 2020;Maioli et al, 2023). Since a variety of elasmobranch species collectively show fidelity for specific reef sites, the benefits of protecting these locations are obvious (Luo et al, 2012;Dulvy et al, 2014;Friedlander et al, 2022). Identifying these reefs and characterizing the environmental and spatiotemporal drivers that underpin elasmobranch reef-use can help tailor regional fisheries policies to benefit their conservation (Schlaff et al, 2014;Filous et al, 2017;Heupel et al, 2019).…”

“…Changes to the water temperature, tide, moon, and currents can affect elasmobranch respiration, metabolism, growth, foraging, and reproduction (Schlaff et al, 2014;Wolff et al, 2018;Heupel et al, 2019). The overlapping life histories and spatial/ecological characteristics of some reef-dwelling species mean that they experience and respond to environmental changes over similar spatiotemporal scales (Schlaff et al, 2014;Friedlander et al, 2022;Hsu et al, 2022;Maioli et al, 2023). Reef-resident species can be acutely affected by environmental change (O'Shea et al, 2010;Heupel et al, 2019).…”

Producción bovina de carne y leche en la península de Osa, Costa Rica

“…El territorio peninsular de Osa (1 200km 2 ), comprende las localidades de Puerto Jiménez (41%) del cantón de Golfito, y los distritos de Bahía Drake y Sierpe del cantón de Osa (52,8%) (Instituto Nacional de Desarrollo Rural [INDER], 2017). Se caracteriza por albergar diez áreas silvestres protegidas equivalentes al 34,47% del territorio, de las cuales en el Parque Nacional de Corcovado se encuentra establecida el 2,5% de la biodiversidad terrestre del planeta tierra (Friedlander et al, 2022). Estas características agroambientales, que permiten albergar tal biodiversidad, de igual manera, permitió desde los años 1948 el desarrollo de la ganadería, con el arribo de los primeros pobladores procedentes de Chiriquí (Panamá), los cuales, al llegar se desplazaron a Puntarenas a solicitar permiso para ocupar los terrenos y establecer una hacienda de ganado bovino (H. Franceschi, comunicación personal, 1 de octubre de 2017).…”