Browsing by Subject "regulations"

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    Dusky dolphin (Lagenorhynchus obscurus) behavior and human interactions: implications for tourism and aquaculture
    (2009-05-15) Duprey, Nicholas Matthew Thomson
    Interactions between humans and dusky dolphins in the coastal waters of New Zealand are increasing. My research focused on tourism interactions, with Kaikoura as the study site; and, on habitat use in an active aquaculture area, with Admiralty Bay as the study site. In Kaikoura, companies engaged in commercial cetacean tourism (For Hire Company) have permits issued by the New Zealand?s Department of Conservation, allowing them to take paying customers out to view and swim with wild dusky dolphins. During summer and fall of 2005, I assessed the effectiveness of a voluntary ?rest period? established to give time free of humans to the dolphins. I used a theodolite to track the movements of large groups of dusky dolphins and recorded the arrival, departure and behaviors of all vessels approaching within 400 m of the group. The ?rest period? resulted in a reduction of vessel visits compared to non-rest periods, yet one For Hire Company and private recreational vessels continued to visit dusky dolphin groups during this time. To increase compliance with the voluntary regulation, more education is needed targeting private recreational vessels. Weekend traffic was higher compared to weekday traffic, during both rest and non-rest periods; a large increase occurred in weekend non-commercial vessel traffic. Swimming with calves is prohibited by New Zealand?s Marine Mammal Protection Regulations of 1992, yet 71.4 percent of the swim attempts I observed on-board For Hire Company tours were conducted with groups containing calves. More should be done to reduce the number of swims conducted with groups of dusky dolphins containing calves. In winter of 2005, I used hourly theodolite scans to record the number of dusky dolphin groups using Admiralty Bay, a different near-shore environment with less tourism than off Kaikoura, and with near-shore mussel farms. Groups of dusky dolphins were observed in Admiralty Bay using the full extent of the bay. This re-enforces previous findings that Admiralty Bay is an important winter foraging ground for dusky dolphins, and further aquaculture development in the bay would remove available foraging habitat.
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    Impacts of Vessel Noise Perturbations on the Resident Sperm Whale Population in the Gulf of Mexico
    (2012-07-16) Azzara, Alyson
    The Gulf of Mexico is home to two of the world?s ten busiest ports by cargo volume, the Port of New Orleans and the Port of Houston; and in 2008, these ports hosted a combined 14,000 ships, a number which is likely only to increase. Past research shows that this increase in shipping worldwide has historically lead to an increase in ambient noise level of 3-5dB per decade. Sperm whales in the Gulf of Mexico are considered a genetically distinct, resident population. They have a preference for the Louisiana-Mississippi Shelf region which directly overlaps with the entrance to the Mississippi and the Port of New Orleans. Disruptions from vessel noise could influence feeding and breeding patterns essential to the health of the stock. Data used in this analysis were collected continuously over 36 days in the summer of 2001 from bottom moored Navy Environmental Acoustic Recording System (EARS) buoys. Results showed a significant difference (P<0.05) in noise level between hours with ships passing and hours without. Metrics for 56 ship passages were analyzed to compare duration of ship passage with duration of maximum received level (MRL) during ship passage. Results of that analysis showed an average ship passage of 29 minutes with average MRL lasting 23% of the ship passage and an average increase of 40dB. Lastly, click counts were made with the Pamguard. Click counts for ship passages were completed for 35 min and 17.5 min before and after the estimated closest point of approach (CPA) for each ship. Results showed a 36% decrease in the number of detectable clicks as a ship approaches when comparing clicks detected at intervals of both 35 minutes before and 17 minutes before the CPA; additionally, 22% fewer clicks were counted 30 min after the ship than 30 min before (results significant at the P=0.01 level). These results indicate a potential change in sperm whale behavior when exposed to large class size vessel traffic (e.g. tankers and container ships) from major shipping lanes. Recommendations for addressing this issue are discussed.