[Coral-List] Mass spawning in Puerto Rico

[Hernandez Edwin]

Dear coral listers:
   
  Hola! Below is a summary of our observations of coral spawning activities in Puerto Rico during this week.
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  Summary of mass spawning observations in Puerto Rico during the week of August 19 to August 23, 2008 by the Coral Reef Research Group, at the Center for Applied Tropical Ecology and Conservation, University of Puerto Rico – Río Piedras Campus, and several of our collaborators.
   
  Monday, August 18, 2008 (2nd evening after full moon)
   
  Observations were made at Arrecife El Banderote, Bahía Tamarindo, at the Luis Peña Channel No-take Natural Reserve, Culebra Island (0.5 – 4.0 m), 28 km approximately east of Fajardo, northeastern Puerto Rico during the evening for spawning activity in staghorn coral (Acropora cervicornis) and elkhorn coral (A. palmata). Winds E-NE <10 knots, calm oceanographic conditions. No mass spawning occurred.
   
  Tuesday, August 19, 2008 (3rd evening after full moon)
   
  Observations were made at Arrecife El Banderote, Bahía Tamarindo, Culebra Island (0.5 – 4.0 m), during the evening for spawning activity in staghorn coral (Acropora cervicornis) and elkhorn coral (A. palmata). Low tide, winds E-NE <10 knots, calm oceanographic conditions. No mass spawning occurred.
   
  Observations were also made at a shallow (0.75 – 1.75 m) Acropora palmata reef at Vega Baja, 32 km approx. off western San Juan, PR, in the northern coast, approximately between 19:00 and 22:00. Low tide, winds NE 10-15 knots, swells 3 feet. No spawning was documented.
   
  Wednesday, August 20, 2008 (4th evening after full moon)
   
  Observations were made at a shallow (1.5 – 2.25 m) Acropora palmata reef at Vega Baja, between 19:00 and 22:45. Low tide, winds NE 15-20 knots, swells 3-5 feet, visibility 5 m. Massive spawning of A. palmata occurred between approximately 21:00 and 22:00, with an apparent peak somewhere around 21:15 or so. Spawning was documented to occur in most colonies within heavily dense thickets, either in upper or lower colony branches. Also, in isolated colonies, as well as in several colonies overturned by a major winter storm swell during last March. Several large fragments (>75 cm maximum length) already reattached to the bottom also spawned. No spawning was observed in either loose or reattached smaller-sized fragments.
   
  Thursday, August 21, 2008 (5th evening after full moon)
   
  Observations were made at a shallow (0.75 – 1.75 m) Acropora palmata reef at Vega Baja , approximately between 20:00 and 22:00. Low tide, winds NE 10-15 knots, swells 3 feet. No spawning was documented.
   
  Observations were made at Arrecife El Banderote, Bahía Tamarindo, Culebra Island (3.0 m), during the evening for spawning activity in cultured staghorn coral (Acropora cervicornis) from one of coral farms. Low tide, winds E-NE <10 knots, calm oceanographic conditions. No in situ observations were recorded, but spawn was caught by a gamete trap that was set up overnight and verified the following day.
   
  Friday, August 22, 2008 (6th evening after full moon)
   
  No observations could be made.
   
  Saturday, August 23, 2008 (7th evening after full moon)
   
  Observations were made at Playa Carlos Rosario, at the Luis Peña Channel No-take Natural Reserve, Culebra Island (1.0 – 8.0 m) linear reef between 21:50 and 23:40. High tide, winds NE 15-20 knots and dropping to 10-15 knots, offshore swells 6-8 feet, but 1 foot at diving site. Visibility >15 m. Massive spawning of different species was documented, mostly octocorals such as the black sea rod, Plexaura homomalla (spawned during the entire dive, but with a peak around 23:00), the giant slit-pore sea rod, Plexaurella nutans (22:15-22:30). Spawning was also observed in isolated colonies of the encrusting gorgonian (Erythropodium caribbaeorum), spiny sea rod (Muricea sp.), pillar coral (Dendrogyra cylindrus). 
   
  Spawning was documented only in 2 colonies out of approximately 20 inspected colonies of Montastraea franksi (22:45-23:00), and in 1 physiological fragment out of approximately 50 inspected colonies of M. annularis (23:15). No spawning was observed in any of the 20 or so colonies inspected of M. faveolata. No spawning was either documented in any of the brain corals (Diploria spp., Colpophyllia natans), star coral (Siderastrea siderea), finger corals (Porites spp.), mustard hill coral (P. astreoides), flower coral (Tubastrea aurea), lettuce coral (Helioseris cucullata), or in Madracis formosa.
   
  Lack of spawning or the presence of very limited spawning in some species may suggest the potential of a split spawning event during 2008, with a possible second spawning peak in September. This will need to be verified. However, lack of spawning in the Montastraea annularis complex species requires further study. This species complex did not spawn at all during 2006 and 2007 at coral reefs that suffered major mortality during 2006 following the record-breaking 2005 bleaching event in eastern Puerto Rico. Spawning documented in Montastraea spp. was not the typical mass spawning event. Rather, it was characterized by the presence of isolated gamete bundles in sporadic polyps, and at irregular timing. Observations will be repeated in the same reef next month to determine if this is in fact a split event, or to confirm if in fact we are having another reproductive collapse in M. annularis complex species.
   
  Hope this information is useful for all coral listers.
   
   
  Saludos!
   
   
  E


Edwin A. Hernández-Delgado, Ph.D.
Affiliate Researcher

University of Puerto Rico
Department of Biology
Coral Reef Research Group
P.O. Box 23360
San Juan, Puerto Rico 00931-3360

Tel (787) 764-0000, x-2009
Fax (787) 764-2610

e-mail: coral_giac at yahoo.com