Nature and consequences of biological connectivity in mangrove systems

Abstract

Mangroves are important nursery and feeding areas for fish. Their rich invertebrate faunas render them productive feeding areas, while their shallow waters and structural complexity provide sanctuary habitats at a variety of scales. However, in most parts of the world mangroves are available to fish for only part of the time because they are alternately inundated and exposed by the high-tide/low-tide cycle. As a result, few fish can use mangroves exclusively but must migrate in and out of the mangroves with the tide, occupying alternative habitats when mangroves are unavailable. These movements connect the mangroves and the alternative habitats to form an 'interconnected habitat mosaic'. Living in a habitat mosaic puts limits on the patterns of life possible in mangrove systems, complicates trophic structures, and creates the need for tactics and strategies to meet the challenges imposed by movement among components of the mosaic. Moreover, this biological connectivity means that understandings of trophic relationships, life-history strategies, predation and mortality, and patterns of distribution and abundance must be set in a spatially and temporally variable context. Despite the obvious consequences and importance of biological connectivity in mangrove ecosystems, it has often not been given appropriate consideration in the development of theories and paradigms. KEY WORDS: Biological connectivity · Mangrove · Estuary · Fish · MovementResale or republication not permitted without written consent of the publisher

Variación entre hábitats de la densidad y composición por tallas en peces de arrecife de la región noroccidental de Cuba

“…The presence of adult fish in all sampled habitats was consistent with Sheaves (2005) and Chittaro et al (2005) conclusions that the term 'nursery area' applied for mangroves and seagrass habitats should be used with discretion. Based in our results, we consider the term 'adult habitat' applied for coral reefs should be used also with discretion.…”

Habitat connectivity and spatial complexity differentially affect mangrove and salt marsh fish assemblages

“…Both habitats are similarly characterised by widely fluctuating environmental factors, such as temperature, salinity and currents (Cattrijsse & Hampel 2006, Nagelkerken et al 2008. It is important to clarify the differences in tidal regime between IndoPacific (mesotidal) and Caribbean/Meso-American (Gulf of Mexico) mangroves (microtidal), and between US Atlantic (mesotidal, dominated by Spartina alterniflora, vegetation flooded on every tide) and European (macrotidal, diverse community of halophytes, vegetation flooded only on spring tides) salt marshes (Sheaves 2005, Cattrijsse & Hampel 2006, Unsworth et al 2007a.…”

Connectivity in reef fish assemblages between seagrass and coral reef habitats

“…Most of these studies were from subtidal areas where connectivity among habitats is permanent. The limited number of studies conducted in South East Asia are from intertidal habitats, where seagrasses commonly lie adjacent to coral reefs on fringing reefs and lagoons, offering temporary habitat and therefore potentially different functions for reef fishes (Sheaves 2005, Unsworth et al 2008, 2009a.…”