Biomass and Growth of the Turtle Grass Thalassia testudinum (Banks ex Koenig) in a Shallow Tropical Lagoon System, in Relation to Tourist Development

摘要

Thalassia testudinum biomass, blade growth and production in relation to environmental nutrient concentration were studied in perturbed (Bojorquez Lagoon) and relatively pristine areas (Cuenca Norte) of the Nichupte Lagoon System, which is surrounded by the tourist complex of Cancun, Mexico. Biomass core samples were taken in May 1991, and blade growth and productivity were studied from July 1991 until January 1992. No differences in water soluble nutrients were found between the Bojorquez Lagoon and Cuenca Norte. However, at the more perturbed stations in the Bojorquez Lagoon, sediments contained more phosphorus, which was reflected in higher total phosphorus content of the blades of T. testudinum at these stations. Thalassia testudinum blades attained higher growth rates and greater length at the more perturbed stations, and blade growth rate was positively correlated to blade phophorus content The plant's total biomass and shoot density were lower at the perturbed stations than at the more pristine ones. However, at the perturbed stations, aboveground green blades comprised a larger proportion of the total biomass. Areal blade biomass and blade production were similar for all sampling stations, notwithstanding differences in environmental nutrient conditions.