Trophic relationships among fish assemblages on a mudflat within a Brazilian Marine protected area

Abstract

Trophic relationships among fish assemblages on a mudflat within a Brazilian Marine protected areaThe present study deals with the temporal variations in diet and the trophic guilds of dominant fish species on a tidal mudflat during the dry and rainy seasons. We sought to classify the diet composition of 17 species in the Mamanguape river estuary, northeastern Brazil, identifying the dominant food components and evaluating the effects of seasonality on the guild organization. Diets varied little between species and seasons, though they seemed to be more heterogeneous during the rainy season. Five primary feeding guilds were identified, in accordance with the importance of prey in the diets: (1) Detritivore, (2) Zooplanktivore, (3) Zoobenthivore-epifaune, (4) Zoobenthivore-infaune, and (5) Piscivore. Most fishes fed on a diverse range of food items but relied heavily on zooplankton prey. Several fish species showed a tendency to a specialised diet, with almost all species showing some degree of opportunistic feeding. A high degree of diet overlap was found among some species; however, the presence of exploitative competition could not be determined. AbstrActZooplanctívora, (3) Zoobentívora-epifauna, (4) Zoobentívora-infauna, e (5) Piscivora. A maioria dos peixes predou uma variada gama de itens alimentares, mas fortemente baseados em presas do zooplâncton. Alguns peixes apresentaram tendência para uma dieta especializada, com quase todas as espécies mostrando algum grau de alimentação oportunista. Um alto grau de sobreposição de dieta foi encontrado entre as espécies; no entanto, a ocorrência de competição por exploração não foi observada. resumoDescritores: Dieta, Ecologia alimentar, Comunidades de peixes, Sobreposição alimentar, Estuário.

Effects of ocean warming, eutrophication and salinity variations on the growth of habitat-forming macroalgae in estuarine environments

“…Afterwards, mixtures of seawater with different salinities produced the desired salinities (Yokoya et al 1999b). This salinity range was established according to Campos et al (2015), who recorded a salinity range between 10 and 42 PSU in the estuary from the Barra do Rio Mamanguape Environmental Protection Area. Salinity was measured with a handheld refractometer.…”

“…These macroalgae, along with microalgae, represent a major source of primary productivity in mangrove ecosystems (Karsten et al 1994a), as they produce organic matter and participate in nutrient cycling (McClusky & Elliot 2004). Furthermore, they act as microhabitats for several organisms, mainly protists and invertebrates (García et al 2016;Borburema 2017;Vieira et al 2018) and can be indicators of environmental quality (Melville & Pulkownik 2006;Fontes et al 2007;Melville & Pulkownik 2007) and food resource for consumers (Campos et al 2015).…”