Bloom or Bust: Retrospective Analysis of the Giant Jellyfish, <i>Nemopilema nomurai</i> (Scyphozoa: Rhizostomeae), Ecology in the East Asian Marginal Seas

<p>The Giant Jellyfish, <em>Nemopilema nomurai</em>, is a large-bodied bloom-forming jellyfish that occurs in the semi-enclosed basins of the East Asian Marginal Seas. <em>N. nomurai</em> has bloomed more frequently in the past 20 years than in any period previously recorded. In Japan, recent <em>N. nomurai</em> 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 <em>N. nomurai</em> 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 <em>Rhopilema esculentum</em>, a very similar species to <em>N. nomurai</em>, 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 <em>N. nomurai</em> 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.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Ocean Science and Technology

Year dc:date.available

2016

Author dc:creator

• Yoder, Naomi

Contributors dc:contributor

• William Graham
• Danielle Greenhow
• Vernon Asper

• Nemopilema nomurai
• jellyfish blooms
• medusae
• rhizostomes
• Aquaculture and Fisheries
• Biology
• Ecology and Evolutionary Biology
• Marine Biology
• Oceanography

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/264

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1287