Distribution, Abundance, and Habitat Use by the Dwarf Seahorse, Hippocampus zosterae, along the Texas Coast

Purpose/Objectives

This project will assess the distribution, abundance, demographics, and habitat associations of the dwarf seahorse in major bay systems along the Texas coast.

Study Area

Coastal Texas

Project Period

2019 – 2020

Description

The dwarf seahorse (Hippocampus zosterae) is a small member of the Family Syngnathidae that resides in seagrass beds found within inshore bays and coastal flats. They reach a maximum length (height) of 2.5 cm. Their range includes the entirety of the Gulf of Mexico—from the Atlantic coast of Florida to eastern Mexico including the Bahamas—but they are most common throughout estuarine environments. 

Dwarf seahorses are currently a candidate species for federal threatened and endangered listing. The dwarf seahorse's documented distribution is intermittent throughout its range and abundance seems to be sparse with a large need to fill in these gaps to help make a listing decision. Based on limited data the species appears to be declining due to a combination of factors including the loss of seagrass habitat and targeted harvesting for sale in commercial markets. Seagrasses provide essential habitat that is heavily utilized by dwarf seahorses.

In order to better assess the current status of dwarf seahorses in Texas, information on the distribution, abundance, demographics, and habitat use of this species throughout the Texas coast needs to be collected using intensive field surveys that employ more efficient gear in a variety of habitats. These data are needed by resource management agencies for determining the conservation needs of the dwarf seahorse and to better inform future projects that will contribute to the long term population viability of this species.

Publications and Presentations

Dennis, W.G., Mussmann, S., Fedrizzi, N., Stephens, B., Oakley, J., and Guillen, G. 2022. Genetic ecology of the dwarf seahorse (Hippocampus zosterae) in Texas. Texas Academy of Science, 125th Annual Meeting, Houston, TX. Poster.

Lesher, S.C. 2022. Habitat use, distribution, and density of dwarf seahorse (Hippocampus zosterae) populations along the Texas gulf coast. University of Houston-Clear Lake.

Lesher, S.C., Oakley, J., and Guillen, G. 2022. Dwarf seahorse (Hippocampus zosterae) distribution, abundance, and sampling gear catch efficacy in Texas. Annual Meeting of the Texas Chapter of the American Fisheries Society, Hunt, TX. Poster.

Lesher, S.C., Oakley, J., and Guillen, G. 2022. Relationship between seagrass and dwarf seahorse (Hippocampus zosterae) abundance and distribution in Texas. Texas Academy of Science, 125th Annual Meeting, Houston, TX. Presentation.

Oakley, J.W., Lesher, S., Ulibarri, R., and Guillen, G. 2022. Distribution, density, and habitat association of the dwarf seahorse (Hippocampus zosterae) in Texas. Texas Bays and Estuaries Meeting, Port Aransas, TX. Presentation.

Oakley, J.W., Lesher, S., Dennis, G.,  Ulibarri, R., and Guillen, G. 2022. Distribution, abundance, and habitat use of the dwarf seahorse, Hippocampus zosterae, along the Texas coast. Final Report. Submitted to Texas Parks and Wildlife Department, Contract 526332. EIH 21-001, 78 pp.

Project Sponsors

• Texas Parks and Wildlife Department