The Relationship Between
Sea Surface Temperature and Sea Height on Strandings of Harbor Porpoise
Along the North Carolina Coast
Dr. Aleta Hohn
NOAA Beaufort Laboratory
101 Pivers Island Road
Beaufort, NC 29815
Tel: 252-728 8797 or 8732
Interns for the summer of 2004 will assist with determining whether
an unusually high number of strandings of harbor porpoise during the
winter of 1999 was due to an unusual juxtaposition of oceanographic
features in the western the mid-Atlantic. The goals are to investigate
whether a narrow band of cold water near shore followed by a strong
warm water front results in higher numbers of stranded harbor porpoise
than when the front is further offshore. Further, interns will examine
the effects of wind speed and direction on both sea surface temperature
and strandings. Positive results may allow for development of a model
that predicts relative numbers of harbor porpoise strandings. This question
has been a concern because an alternative explanation for unusually
high numbers of strandings is entanglement of porpoises in gillnets
along the mid-Atlantic coast. The interns will work on compiling extracted
sea surface temperature (SST) and wind data, creating graphs and GIS
plots, and assisting with analysis of the data. Only one other episode
of alarming numbers of strandings of harbor porpoise in North Carolina
has occurred in recent times and that was in 1977. Interns will use
SST and wind data for years when it was available to ensure that the
convergence of oceanographic events seen in 1999 did not occur in other
years when high numbers of strandings also did not occur. Although comparable
data do not exist for the 1970’s, oceanographic sampling cruises did
collect data that may be useful. Access to these results will require
a literature search.
Required skills:
Interns should
have a background in the natural sciences (biology, geology, oceanography)
and statistics, with knowledge of Geographic Information System (GIS).
An interest in applying remotely-sensed data to studies of marine mammal
strandings in also valuable. In addition, the interns will have the
opportunity to participate in field activities including small boat
surveys for bottlenose dolphins and stranding responses. A strong background
in computers with experience using GIS is preferred, but not essential.
All necessary training to complete the tasks will be available for the
duration of the internship. Interns should be familiar with remotely
sensed data including sea surface temperature and wind. Familiarity
with statistical and numerical software packages such as MatLab, SAS,
and SYSTAT would be beneficial.