Wednesday, October 23, 2013

Loggerhead sea turtle release videos - Gulf Stream


After we permanently transferred our unreleasable adult loggerhead sea turtle "Christi" to a larger exhibit at Dallas World Aquarium in 2009, we began to partner with NC aquariums to acquire juvenile sea turtles that we could display for three years and then be released back into the wild. The previous two sea turtles we have displayed at the VLM - Virginia and Abby - have originated from the North Carolina Aquarium at Pine Knoll Shores, including the most recent juvenile (unnamed as yet) we acquired on our trip to release Abby.

A sea turtle nest roped off in Duck, NC

NC Aquariums has an excellent support network of volunteers and trained staff that monitor loggerhead nesting sites along the coastal beaches. They not only protect the nests from being disturbed, but assist the hatchlings to reach the water safely and collect valuable data in the process. The vast majority of hatchlings emerge from the nests healthy and able but many hatchlings do not successfully extract themselves from the nests and may remain buried unless assisted. Once the hatchlings have vacated the nests on their own, the nests are excavated for the stranglers which are then brought back to the aquariums to be nursed back to health or held until they can be released.

A bin of loggerhead hatchlings ready for release by the NC Aquarium

A few of the rescued juvenile turtles are loaned out to other public facilities to serve as educational ambassadors in such places as: Pittsburgh Zoo and PPG Aquarium, Newport Aquarium, Mystic Aquarium, Monterey Bay, and the VLM. Some facilities display the turtles as juveniles and return them after one year; we display the animals for up to three years and then return them to NC for release, and in "Abby's" case, to be affixed with a satellite tag.

Above: VLM Aquarist Patrycja Lawryniuk attaches the satellite tag with epoxy
Below: Close up of the tag that will transmit Abby's location when she surfaces

Just last week we joined these other facilities and their sea turtles at Pine Knoll Shores to release our sea turtle "Abby" along with the others back into their native waters. This time of year the water has begun to cool, so we chartered a SCUBA boat from Discovery Diving  in Beaufort, NC that took us 36 miles offshore in search of warmer Gulf Stream waters. After a three hour boat ride we took turns releasing these beautiful, prehistoric creatures out into the wild. One by one, each facility had the honor of releasing the turtles in their care back into the ocean. Fortunately, I brought along a wet suit and small underwater camera to capture the releases on film.

A hatchling at release

video



video 

The ocean can make one feel very small, especially untethered miles and miles offshore. The expanse seems infinite. But sea turtles are here after all these millions of years because deep within them lies the knowledge and instinct to survive out there, to find food, to find each other. As Abby glided off into the emerald sea far beyond my reach and out of site, in the last few seconds I would see her - after seeing her and caring for her daily for three years, I caught the final glimpse of who she really is and what she is meant to do; a small thing really. She flapped briefly to gather speed, to test her freedom and then spread her back flippers and glided with the current, slipping weightless, riding the powerful current to some unseen destination with no hesitation or fear.

video

As of 10/24/2013, Abby has traveled a total distance of 693km (that's about 430 miles!)! You can follow her progress at http://www.seaturtle.org/tracking/?tag_id=128947



Saturday, October 5, 2013

Redbreast sunfish fry development

A large male redbreast Lepomis auritus in breeding colors

The term "sunfish" generally refers to fishes from the Family Centrarchidae, comprised of 30 species (including several bass species and crappie), but to most people "sunfish" are species from the Genus Lepomis: bluegill, pumpkinseed, longear, warmouth, redear, green, and redbreast sunfishes. To further complicate matters, Lepomis species can - and often do - hybridize with each other especially in captivity (see below). 
 A large male pumpkinseed/redbreast hybrid Lepomis gibbosus on his nest

Most sunfishes spawn in early to mid summer, when the water temperatures begin to approach 70 degrees F. However, in captivity many species - not just sunfishes - are triggered to spawn at unusual times of the year, due to unnatural light cycles and seasonal temperature fluctuations within the facility. For example, two species of sunfish in our Woodland Pond exhibit, the pumpkinseeds and redbreasts are currently spawning, but are several months past their spawning period in the wild.

Breeding or "nuptial" males of all sunfish species fan out broad, saucer-shaped nests with their tails in hopes of attracting a female. The males then aggressively guard these nests which are often quite close together, and chase off all intruders. During this period males become brilliantly colored, showing off their best and brightest for the ladies. If the male successfully attracts a mate, he will fertilize from 1000's to 10's of thousands of eggs, depending upon the size of the female (and species), which she has deposited in the nest. After releasing her eggs, she moves on with no further commitment to the young. The males remain to guard their young from predators as the young develop from eggs to yolk sac larvae to free-swimming larvae. Once the young are swimming and feeding on their own, the job of the male is finally done.

 Eggs are approximately 1 mm


Redbreast fry that have just lost their yolk sac

Fry one week later ( 2 -3 weeks total)
...another week older (4- 5 weeks)
Fry seven to eight weeks after hatching.