|The Transect Line - October 2012||Newsletter Archive|
|Reef Check Spotlight: A New Fish on Catalina Island|
|By Reef Check California Director, Dr. Jan Freiwald
In October, a fish species never-before recorded in California waters was observed off Catalina Island. Ken Kurtis, a diver from the Los Angeles area, was shooting some underwater photos in the shallow waters off Catalina when he noticed a fish that did not quite belong. What he saw was a small blue damselfish (same family as the garibaldi - Pomacentridae), with a patch of greenish-yellow extending from its head onto the forward part of its dorsal fin and a translucent white tail. He took video of the fish and reported it to other divers at one of Reef Check’s partner organizations, the Long Beach Aquarium of the Pacific. The individual was quickly identified as a juvenile whitetail damselfish (Stegastes leucorus) by several experts.
To confirm Ken’s first observation of the species in California, Dr. Bill Bushing went out diving to capture more video. He located the individual and corroborated the identity of the species. Dr. Giacomo Bernardi, a Molecular Ecologist at UC Santa Cruz who has collected genetic samples of this and its two closely related sister species from their native range, and has studied their population distributions extensively, states that the three species form the whitetail damselfish species complex that partition between islands. They are interesting because they demonstrate a pattern of speciation (i.e. evolution of new species) first discovered by Darwin in the Galapagos, but rarely found in fishes. Stegastes beebei (named after William Beebe, the author of World's End, his narrative of an epic trip to Galapagos) is found in the Galapagos Islands and adjacent areas, Stegastes baldwini is restricted to Clipperton Island, a small island due south of Baja California, and then this species Stegastes leucorus, that is found at the Revillagigedo Islands, mainland Mexico, Guadalupe Island, and now Catalina!
According to Bernardi, the closest location that this individual could have come from would be Guadalupe Island off the coast of Baja California – a 300 mile journey through the open ocean. Reef fish, such as this damselfish, go through a larval phase after they hatch, during which the tiny organisms swim in the open ocean before returning to settle on a near-shore reef. The whitetail damselfish typically spends about 20 days as pelagic larvae in the open ocean before it needs to find a reef to grow up on. Once it settles onto a reef, a whitetail damselfish may grow to lengths of about 14 centimeters and live up to 19 years. Dr. Bernardi may try to collect a (non-lethal) genetic sample of this individual. He would then compare this to his database of genetic samples from the fish’s native range to positively identify where the individual came from. In any case, this fish had to have travelled a great distance, and it is unlikely that only one individual would make this long and unusual journey. Although this is the first known recording of a whitetail damselfish in California waters, we may be seeing more of them around Catalina in the future.
This find demonstrates how the presence of well-trained divers who are familiar with the local species can lead to new discoveries, and how they help keep an eye on our local marine environments and the ways they continuously change. This has been a great find Ken!
Comment on this article
|Reef Check Malaysia Hosts Regional Coral Reef Management Workshop|
By Reef Check Malaysia
|Biosphere Expeditions Shows Remarkable Coral Reef Recovery in the Maldives|
|By Biosphere Expeditions & Reef Check Maldives Coordinator, Dr. Jean-Luc Solandt
Scientists who have been surveying reefs around the Maldives in the Indian Ocean say the level of recovery in recent years has left some reefs with more live coral cover than before a catastrophic bleaching event in 1998.
Last month, Biosphere Expeditions, an international conservation non-profit organization and long-time Reef Check partner, sent scientists from the Marine Conservation Society (MCS) and the Maldives Marine Research Centre to the islands to examine previously bleached coral.
Coral bleaching – where corals lose their color and are left white or ‘bleached’ - can lead to weakened and dead corals. Bleaching is thought to be the result of increased water temperature, leading to coral ‘stress’.
Biosphere Expeditions set up a research project on the islands, enlisting the expertise of Dr. Jean-Luc Solandt, MCS Biodiversity Officer, as the project’s lead scientist. This year the focus was on undertaking repeat Reef Check surveys at areas first surveyed before and during the bleaching in 1998 that killed most shallow water corals completely.
The project found that unlike the results recently published from The Great Barrier Reef, which found that coral cover there had been reduced by over 50% in the last 27 years, the more isolated, offshore and clean waters of the Maldives appear to offer better conditions for coral recovery.
The Great Barrier Reef report highlighted three main causes of coral death: outbreaks of coral-eating starfish, mass bleaching of corals, and major storms. However, the Maldives has been different in terms of the number and severity of impacts. The Reef Check surveys this September, carried out by volunteers from all over the world, show that many reefs have recovered to populations in excess of 60% live coral, and that at one site the coral cover is greater now than in 1997.
Dr. Jean-Luc Solandt said, “Although our surveys aren’t as comprehensive in scale and number as those from the Great Barrier Reef, we have witnessed a promising recovery in the reefs we’ve visited. The number of chronic impacts to the reefs of the Maldives are fewer than those to the Great Barrier Reef, and that has probably resulted in this more positive response to the initial bleaching event die-off in the sites we visited in Ari Atoll.”
However, Dr. Solandt warns conservationists and local managers in the Maldives that they cannot be complacent.
“There is overfishing of large predatory fish and further ocean warming events on the horizon, and some of the reefs nearer to Male’ appear not to have recovered as extensively as those further afield.”
Dr. Matthias Hammer, Founder and Executive Director of Biosphere Expeditions, says that whatever the state of the Maldives reefs are now, it’s the outlook that’s important. “Even though the Maldives reefs are generally in waters of excellent purity from man-made pollutants and are seldom hit by coral-damaging storms or attacks by coral eating starfish, the consistently high sea temperatures [averaging 29 degrees Celsius] around the Maldives could lead to bleaching once again if temperatures reach over 30 degrees for any length of time. Without wanting to spread doom and gloom, the prospects of sea-level rise and ocean acidification have the power to remove the Maldives from the map.”
Further surveys will be carried out in 2013. Volunteer divers, who do not need any special skills to help with this research, can find out more via www.biosphere-expeditions.org/maldives.
As part of this year’s expedition, MCS completed the training of 12 new Maldivian Reef Check surveyors, including two who were awarded the highly sought-after scholarship to be aboard the MV Carpe Diem on the trip. The collaboration consisted of four key partners: MCS provided the scientific training; Biosphere Expeditions, who organized the expedition and recruited international volunteers to join; Maldives Marine Research Centre (MRC), who provided the in-country trainees; and Soneva, a conservation-aware local resort who funded the two scholarship awards. At the conclusion of the trip, two individuals from MRC were certified as Reef Check trainers, thus ensuring that the legacy of Reef Check remains strong in the country.
Comment on this article
|OceansWatch Continues its Marine Conservation Work in the Solomon Islands with an Expanded RC Program|
By Glenn Edney, Reef Check Solomon Islands
|First Jordanian EcoDiver Team Certified|
Dr. Mohammed Kotb, a coordinator for Reef Check Egypt, recently finished an EcoDiver training program in Aqaba, Jordan in which three members of the Aqaba Marine Park Rangers were certified as Reef Check EcoDivers. The Rangers had previously participated in surveys in the Red Sea with Dr. Kotb, but have now officially become the first EcoDiver team in Jordan and will be able to conduct surveys on their own. Congratulations to the new team!
|If you do not wish to receive future e-mails from us, you can unsubscribe at any time by clicking here.
To ensure delivery, please add our e-mail address email@example.com to your Address Book. Thank You.
Reef Check P.O. Box 1057 Pacific Palisades, CA 90272-1057 USA