Marine Ecology

Waiheke Island, New Zealand

Individuals applying for a permit to build a 160+ birth marina in Matiatia Bay submitted an assessment of the impact such a marina would have on the marine environment to the Environmental Court. A group of concerned citizens hired me to analyse the scientific merits of the applicant’s assessment of environmental impact. In short, I found that the assessment lacked sufficient baseline data upon which to make informed decisions about the marina’s impact on Matiatia Bay’s marine habitats.

Apart from my role as expert witness before the Court, it occurred to me that there was little or no data available that describe ecosystems of Matiatia Bay, and that such data could be useful to the broader community, including schools and local government councils. As time allows, I am working with others to collect preliminary baseline data of Matiatia’s marine life and habitat systems. My friend Thomas Greve generously created a web site to disseminate our findings, which remains a work in progress: Matiatia F.Y.I.

Recruiting giant clams to their natural habitat

Once giant clams reach a certain size, what is the best way to transfer them directly from land-based raceways to coral substrata in the lagoon? After several attempts at building a protective environment for young clams until they anchor themselves to coral substrata, I designed a protective cage using wire mesh, shade cloth, copious amounts of zip-ties and – of all things – hula hoops. Over a 3-week period, we found that 2- and 3-year-old juvenile clams > 27 mm were more likely to survive, but mortality of smaller 1-year-olds was unacceptably high. In the longer term, results showed that almost 42% of the reintroduced juveniles survive the first 1.5 years in the wild. A short video best communicates the deployed methodology:

Ecological Assessment of the Aitutaki Lagoon

This report was prepared for the Cook Islands Ministry of Marine Resources (MMR) using proprietary data that precludes its release to the public. However, the scope, methodology and summary results do not breach confidentiality. Parameters investigated included: Chlorophyll a, enterococci, dissolved organic nitrogen (DIN), dissolved reactive phosphorous (DRP), pH, dissolved oxygen (DO), salinity, water temperature, and total suspended solids (TSS). Scores for each water quality factors relevant to giant clam biological, physiological and metabolic requirements at 7 sites in the lagoon were based on 2 years of mean data from each location, where 3 = excellent (green), 2 = average (yellow), and 1 = poor (red). Site scores were as follows: