By Gregg Bragg, The Island Connection Staff Writer
Photos courtesy of Dolphin Angels
South Carolina’s coast is home to myriad species of marine life including the bottlenose dolphin (Tursiops truncatus) and right whale (Eubalaena glacialis). Interest in both species is high and definitive information so hard to come by, it prompted the Kiawah Island Naturalists Group and the Kiawah Conservancy to schedule a presentation at the Sandcastle last April.
Wayne McFee, a conservationist with the National Oceanic and Atmospheric Administration Coastal Marine Mammal Assessments department was happy to oblige.
The bottlenose dolphin is very much at risk in the Lowcountry, said McFee. There are two “estuary” pods of dolphin, one at each end of Kiawah, for example, and the entire SC coast is dotted with similar family units. What McFee called “dolphin basics” include:
1. Life span – Males: 40-45 years, Females: at least 50 years
2. Length – Male: 8-13 ft., Female: 7-12 ft.
3. A one-year gestation period results in calves weaned at 18-20 months at three year intervals
4. Status of population: considered depleted
The fact estuary pods don’t migrate provides some protection from diseases passed along by pods that do, but South Carolina still averages 50 strandings each year according to McFee. However, there are other threats that affect both dolphins and whales.
1. Coastal development (construction in sensitive areas)
2. Noise (shipping and construction – many stranded dolphins are found to be deaf)
3. Climate change (less food/more competition)
4. Disease (morbillivirus and brucella often passed by migrating pods)
5. Contaminants (plastics, marine debris and other chemicals)
6. Fisheries (Dolphins taking bait off hooks/competition)
7. Boat and Ship Traffic (boat/ship strikes)
8. Illegal feeding and harassment (don’t feed the dolphins)
9. Balloons (mistaken for food and ingested) Contaminants, continued McFee, are particularly insidious. Male dolphins are unable to “dump” toxins they ingest, which build up over time and may contribute to strandings. Females can “dump” toxins but it usually ends up in the systems of their first born and again, may contribute strandings. Whales have all of this to contend with and more.
Right whales were assigned their common name because they were deemed the best species to hunt, beginning as early as the era of tall ships, said McFee. Most species of whales sink like Moby Dick when killed, floating back to the surface only after enough gases have built up to make them buoyant. Right whales, however, stay on the surface, making them easier to harvest.
The trait contributed to reducing the right whale population to just 300 individuals (originally estimated to be 10,000). Although the population now stands at 500, the current trend still ends in extinction. Studying the problem is the priority for McFee.
The April presentation had originally been scheduled for much earlier in the year. McFee was called away at the time to cover an Unusual Mortality Event. Defining the term was the “darkest before the dawn” portion of his visit. McFee defined the term as;
1. A marked increase in the magnitude or a marked change in the nature of morbidity, mortality or strandings when compared with prior records.
2. A temporal change in morbidity, mortality or strandings occurring.
3. A spatial change in morbidity, mortality or strandings occurring.
4. The species, age, or sex composition of the affected animals is different than that of animals that are normally affected.
5. Affected animals exhibit similar or unusual pathologic findings, behavior patterns, clinical signs, or general physical condition (e.g., blubber thickness).
6. Potentially significant morbidity, mortality or stranding is observed in species, stocks or populations that are particularly vulnerable (e.g., listed as depleted, threatened or endangered or declining).
Fortunately, the news isn’t all bad. McFee is a member of and/or works with several groups which are working to make a difference. The Sighting Advisory System has been instituted to monitor marine animals in high density areas. SAS is augmented with the Early Warning System.
EWS is used to advise ships when there is activity in their path. Interested in helping whales and dolphins? There is plenty you can do.
1. Report strandings to (800) 922-5431 page (843) 820-0612.
2. Do not push a live whale or dolphin back to the sea
3. Do not feed dolphins
4. Report illegal dolphin feeding to (843) 762-8592
5. Remove marine debris (rope, plastic, netting, etc.) from the water and beaches
For more information contact NOAA or, sparingly, email Wayne McFee using the address firstname.lastname@example.org.