Since the 2011 IMARES Wageningen UR overview of marine invasive species in the Dutch Caribbean, the invasive seagrass Halophila stipulacea has been additionally documented on three additional Dutch islands. While in 2011 it was only known from St. Maarten and Bonaire, it has now been confirmed for Aruba, Curacao and St. Eustatius.
Photo: Researcher Dolfi Debrot standing in a lagune, the typical habitat of the seagrass in Curacao.
The seagrass Halophila stipulacea is typically found in habitats protected from wave energy on the lee side of islands either due to depth (down to 26 m depth in St. Eustatius) or in sheltered lagoons. These findings have been incorporated into a regional assessment now in press with the journal Aquatic Botany.
The seagrass appears to be a strong invader and occupies space typically in the form of dense monospecific patches, with coverage typically upwards of 85%.
At present, IMARES Wageningen UR is conducting some preliminary evaluations in Bonaire on whether or not the species is consumed by the green turtle and on how it may affect seagrass nursery fish abundance.
Widely spread seagrass
In the 10 years since first being documented in the Caribbean, the researchers have found that the species has widely spread throughout the eastern Caribbean (19 different islands), and implicate commercial and recreational boat traffic as its most likely means of dispersal.