Structural complexity of tropical seagrasses meadows in a temperate lagoon in the Gulf of Mexico. A landscape ecology approach

Seagrass meadows are sites that help mitigate the effects of climate change. The protected area of the Laguna Madre of Tamaulipas is an important site for its biodiversity, which has undergone changes both in the structure and distribution of its seagrass meadows. Five seagrass species were found (Halodule wrightii, Syringodium filiforme, Thalassia testudinum, Ruppia maritima and Halophila engelmannii), forming multispecific meadows. The south zone presented the longest and broadest leaves, but the lowest biomass. Biomass was greatest in the center zone, whereas the highest density were observed in the north zone. The structure analysis showed that the longest and the densest seagrass meadows were S.filiforme. The greatest biomass was recorded for T.testudinum. The meadows with the greatest cover consisted of H.wrightii-S.filiforme. There is little fragmentation of the landscape, and a large succession of species. This indicates change processes, due to the variation in environmental conditions, caused by anthropic modifications, in the lagoon. Due to its importance as an environmental bioindicator, it is necessary to monitor changes in the patterns of structure, fragmentation and succession of species. The present research provides evidence of the change in the distribution of tropical seagrass cover, which may be related to the tropicalization of temperate ecosystems and the need to conserve these habitats.