Date of Award

Fall 12-2016

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Ocean Science and Technology

Committee Chair

Dr. William Graham and Dr. Danielle Greenhow

Committee Chair Department

Ocean Science and Technology

Committee Member 2

Dr. Vernon Asper

Committee Member 2 Department

Ocean Science and Technology

Committee Member 3

Dr. Luciano Chiaverano

Committee Member 3 Department

Ocean Science and Technology

Committee Member 4

Dr. Jennifer Walker

Committee Member 4 Department

Biological Sciences

Abstract

The Giant Jellyfish, Nemopilema nomurai, is a large-bodied bloom-forming jellyfish that occurs in the semi-enclosed basins of the East Asian Marginal Seas. N. nomurai has bloomed more frequently in the past 20 years than in any period previously recorded. In Japan, recent N. nomurai blooms were responsible for millions of dollars in lost revenue and equipment damage to commercial fisheries alone. This study statistically analyzed 21 environmental factors in connection with N. nomurai occurrence (using occurrence as a proxy for blooms). Eight factors resulted in a statistically significant or marginally significant (p ≤ 0.10), linear or non-linear relationship with jellyfish occurrence. Significant linear factors were jellyfish aquaculture, kelp aquaculture, benthic structures, Pacific saury fisheries and shellfish fisheries. Significant non-linear factors were chub mackerel, jellyfish, Ohkotsk mackerel fisheries. Jellyfish aquaculture and jellyfish fisheries target Rhopilema esculentum, a very similar species to N. nomurai, and the results of the analysis show that the two species are intertwined ecologically. One of the factors with a significant relationship, jellyfish aquaculture, matched the expected trend (positive linear correlation). Three non-linear significant relationships resulted in a partial confirmation of the expected trend. The results and lack of expected response is likely at least partially due to limitations of the N. nomurai data. The jellyfish dataset was left skewed, and when summarized by year (average occurrences/year), was reduced to nine data points. Analysis of more jellyfish occurrence data, along with continued exploration of the statistical relationships with aquaculture, fishing, and coastal development, is recommended.

ORCID ID

orcid.org/0000-0003-3977-8621

Available for download on Saturday, December 16, 2017

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