Graduation Year

2012

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Marine Science

Major Professor

Pamela Hallock-Muller

Keywords

Coral Damage, Marine Protected Area, Miniseason, Panulirus argus, SCUBA Diving

Abstract

The Spiny Lobster (Panulirus argus) fishery in Florida is closed during the spawning season (March-July) except for a two-day recreational `miniseason' for sport divers in July, several days prior to the opening of the commercial fishing season. In Monroe County, recreational fishers, who possess a valid Saltwater Fishing License with crawfish stamp, are allowed to harvest six lobsters per day, each with a minimum carapace length of 76.2 mm (3.0 inches). During these two days, approximately 50,000 people attempt to catch lobster, and the number of boats visiting the reef has been estimated to be up to 900 times higher than during the regular lobster season.

I quantified incidences of benthic damage that occurred during the August 2011 miniseason, as well as substrate type and benthos affected. Study sites at Eastern, Western, and Middle Sambos, each characterized by spur and groove reefs, represented different levels of protection within the Florida Keys National Marine Sanctuary. The Eastern Sambos is a research only area, the Western Sambos permits recreational SCUBA diving but does not allow harvest of marine resources, and the Middle Sambos allows both recreational diving and lobster harvesting. The "Impact Site", the Middle Sambos, allows lobster harvesting, and "Control Sites", The Eastern and Western Sambos, were off limits to lobster harvesting. All sites were assessed three times before and three times after the miniseason at four locations within each of the three reef areas. Research divers conducted 30-minute, random-swim surveys cataloging incidences and magnitudes of benthic damage and counting legal-sized Spiny Lobster observed on reefs. Data were collected and analyzed using analysis of variance following the `Before-After, Control-Impact, Paired-Series' (BACIPS) design.

I found an increase in the incidences of benthic damage at the Impact sites in the three surveys conducted after the miniseason, while no significant change occurred in Control sites. This suggests that detectable benthic damage associated with lobstering activity occurred during the miniseason, at least partly as a consequence of diver impacts while searching for and capturing Spiny Lobster. In addition to SCUBA gear, divers typically also bring gloves, a three-foot (92 cm) tickle stick, a hand net, a lobster gauge, and a lobster bag, all of which make buoyancy control more challenging. By actively searching for and attempting to capture Spiny Lobster, which are cryptic and maintain close proximity to the reef, lobster-seeking divers damage the benthos at higher rates than divers engaged in non-consumptive recreational activities.

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