Publication Date

2019-07-26

Availability

Open access

Embargo Period

2019-07-26

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Marine Biology and Fisheries (Marine)

Date of Defense

2019-06-21

First Committee Member

Nelson Ehrhardt

Second Committee Member

Elizabeth Babcock

Third Committee Member

David Die

Fourth Committee Member

David Letson

Fifth Committee Member

David Carter

Abstract

Bycatch mortality from commercial tuna fisheries threatens billfish populations in the Eastern Pacific Ocean, which are also used for lucrative recreational tourism industries. The recreational billfish fishery in Guatemala is characterized by seasonally high daily sailfish catch rates, consistently 2-3 times higher than anywhere else on Earth, and is entirely catch-and-release. The anglers are predominantly tourists, bringing financial contributions to Guatemala. Until now, Guatemala’s government and international tuna management organizations could not consider the value of this sustainable use of billfish resources, because previous estimates were poorly defined and estimated. We used an innovative, market-based technique to estimate the value of Guatemala’s recreational fishery, which eliminates the hypothetical bias that has plagued previous estimates of other billfish resources. Based on charter fishing client transactions in 2017, we estimate that the value of the billfish resources in Guatemala is approximately $1 Million when used for catch-and-release fishing. We also identify factors and variables that support the demand for these services. The predominant aspect drawing anglers to fish in Guatemala is their expectation of high daily catch rates; over half of the respondents self-reported that this was their motivation for choosing Guatemala. Anglers explicitly seeking high catch rates were more satisfied following their fishing trip than those who were motivated by other reasons, despite many over-predicting their success rates. Anglers traveling to Guatemala were also highly experienced; on average, they had been fishing specifically for billfish for 13 years. These factors contribute to our theory that anglers traveling to Guatemala are seeking a unique experience that cannot be expected when fishing elsewhere. We also describe the dynamic environmental conditions supporting the high, seasonal catch rates that draw anglers to Central America. Using tournament Catch Per Unit Effort (CPUE) indices, we found support for the theory that local density and habitat compression affect the recreational catch rates. When the habitat was more compressed, Guatemalan anglers fishing in the yearly tournament saw higher catch rates, indicative of increased fish vulnerability to the surface fishing gear. Here, we suggest that catchability is indicative of very localized conditions, and cannot be applied stock-wide. Our evidence suggests that high seasonal catch rates (in recreational tournaments or for-hire fishing) sampled from a peripheral, small portion of the entire stock distribution should not be interpreted as indicators of sailfish abundance. Instead, these catch rates should be viewed as the foundation of valuable tourism industries, and be preserved as such.

Keywords

billfish; sailfish; environmental valuation; recreational fishing; Guatemala

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