Sea2Shore Notes from the Field
9-15 January 2010 Cuba
James A. Powell, Ph.D.

The objective of this mission was to survey areas by boat along the coasts of Ensenada de Cortes and Golfo de Batabano for manatees on the southern coast of Cuba and to collect general habitat and environmental data. In particular, we wanted to visit the offshore springs of Cayo Los Guzmanes that are reported to be important areas for manatees to obtain freshwater. We also planned to visit Siguanea Bay, our primary study site in order to conduct transect surveys and search for manatee remains that had been reported by fishermen. Due to the passage of a severe cold front and foul weather, we had to change our survey route, skipping Cayo Los Guzmanes and traveling directly to the more protected waters of Siguanea Bay. It was fortunate that we made this change, since we discovered that manatees likely use the constant temperature (based on temperature data taken through the year) brackish water springs in San Pedro River and associated lagoons as a warm water sanctuary.

On 12 January the day after the passage of the cold front, we saw a minimum of 17 manatees in the river system. The San Pedro River flows from the Lanier Swamp and appears to be a major source of freshwater, shelter, a source of preferred food (Halodule sp.) and provides a warm water sanctuary during colder temperatures for manatees using Isla de La Juventud. Though manatees were known to inhabit this area, the critical importance of this river to manatees and estuary was previous unknown. About 18 C water temperature is considered a critical trigger for manatees in Florida to find seek shelter from cold water.

• January 9, 2010 6 AM departed Sarasota by private vehicle for Miami. 10 AM, arrived at Miami airport. 1:30 PM, departed Miami for Havana, Cuba and arrived at 2:30 PM. At 3:30 PM arrived at Comodore Hotel.
• January 10, 2010 8:30 AM I was picked up by a truck from the Center for Marine Investigations (CIM). We drove approximately 3 hours to the town of La Coloma on the southern coast where we met our boat at the Enterprise for Flora & Fauna (FyF) office for the San Felipe Reserve. FyF is the government agency responsible for wildlife conservation. We boarded the chartered boat, called the “Neptuno”, that had come from the Isla de La Juventud (Isle of Youth) to pick us up. We departed the dock at about 3 PM and headed east along the coast. We stopped twice to take environmental data. The air temperature was 16°C (60.8°F), water temperature 19.8°C (67.6°F) , wind speed 10 to 15 kts blowing from the northeast. There was a strong chop. We anchored for the night at El Gato point where manatees are frequently reported, but none was sighted. The air temperature continued to drop dramatically during the night. Crew: Gerardo Lastre Lopez, Abelardo Dominguez, from CIM Dr. Jorge Angulo Valdez & Anmari Alvarez Alemas, Lozaro Garcie Lopez & from FyF Eddy Garcia Alfonso.
• January 11, 2010 The anchor dragged during the night and we drifted about 5 km southwest. At 7:30 AM the sky was relatively clear with scattered clouds, wind blowing from the northeast at 15 to 20 kts, water temperature 18.3°C (64.9°F) and air temperature 15.8°C (60.4°F). Heavy chop. We continued east along the coast to El Gato Point and continued east to a small lagoon behind the point. We were unable to enter because of low tide, but a FyF boat appeared from the lagoon, where they were fishing using a skiff and net (catch was mullet, gray snapper and mojarra). We continued east to a point off the village of Dayaniguas. Because of heavy weather we skipped the islands where manatees had been reported by fishermen to use freshwater springs. We continued directly to Isle of Youth and surveyed the northern side of Barco Lagoon. Because of winds, most of the lagoon was turbid with chop. Air temperature was 14.6°C (58.3°F), water surface was 17.7°C (63.8°F) and salinity 35.2 ppt. We continued south to Los Indio River but the tide was too low to gain entrance. Manatees have been reported from this river. We traveled south to Sigunea Bay with heavy following seas. We decided to enter the harbor at Marina Siguanea rather than anchoring the night. Instead of sleeping on the boat as originally planned, we stayed at the Colony Hotel and the price of the hotel would be deducted from the boat charter (since the boat is operated by the hotel). The cold front continued to pass through bringing very strong north winds.
• January 12, 2010 In the morning winds were calmer and sky clear. I departed the hotel by crew bus and we left the dock at 9:15 AM. We headed south and up the San Pedro River to the second lagoon, Estero de la Piedas, which is fed by several brackish springs. At the southern terminus of the lagoon we disturbed several manatees that dove with a large splash. In the lagoon air temp was 14.6 °C (58.3°F), surface water temp (Ts) 18.8°C (65.8°F), bottom (Tb) 18.8 °C (65.8°F), surface salinity (Ss) 28.4 ppt, bottom (Sb) 28.5 ppt. There were several sightings of manatees about 0.5 km south of the southern end of the lagoon. Two manatees were sighted bottom resting at a spring along the southern most bank of the lagoon. This is also the area where a manatee carcass was reported by fishermen two months ago. Thirty minutes of surfacing intervals were recorded and tended to be 3-5 min in duration. The spring temperature was 21.7°C (71.6)°F Ts, 22.4°C (72.3°F) Tb, Ss 26.3 ppt and Sb27.5ppt, about 90m away surface temp dropped to 19.3°C (66.7°F), Tb 19.2°C (66.6°F) and salinity 26.9 ppt surface and 27.0 ppt on the bottom. There was a 4 degree difference between the surrounding water and the spring. In this particular lagoon, we had about 5 sightings of manatees of at least 8 individuals.. I estimated that there were probably 10-12 individuals in the area. Anmari collected near the spring the skin of a nurse shark and possibly a manatee that had been killed. At 2:30 PM we measured the temperature at another spring near the mouth of the lagoon, Ts 19.2 °C (66.6°F), Tb 20.2°C (68.4°F), Ss 29.2, Sb 29.8. We continued about 3km up the San Pedro River to a small bay, Ts 18.6°C (65.5°F), Tb 23.9 °C (65.0°F), Ss 5.2, Sb 33.5. A freshwater lens covers the saltier water creating a temperature inversion of warmer water. At 3:25 as we departed the bay for the mangrove creek, we disturbed a manatee headed upriver into the bay. At 3:42 we sighted a single manatee in the middle of the river moving downriver. , At 4:15 PM we sighted another individual moving down river, 4:35 PM 200 m further down river another individual was seen and several observations of breaths were observed. At 4:38 a single individual was seen moving downriver. The temperature of the river at this position was Ts 19.5°C (67.1°F), Tb 19.4°C (67.0°F) , Ss 31.1 ppt, Sb 33.6. Finished survey at 5pm and returned to marina and hotel. There were at least 17 manatees observed. A local fisherman who reported the manatee carcass was interviewed that night, he gave the position of two carcasses, one in the southern portion of E. de Piedras and another about 2km south of the mouth of San Pedro.
• January 13, 2010 Departed the hotel at 7:45 AM. The air temperature was 14.6 °C with scattered clouds. Left the dock at 8 AM and traveled directly to E. de Piedras and shut down the engines to drift. No manatees were observed after 45mn of observations. Temperature about 100m from the spring has increased slightly from the previous day to Ts 20.4°C (68.7°F), Tb 19.3°C (66.7°F), Ss 27.6, Sb 28.3 air was 14.6°C (58.3°F). The bottom was explored by snorkeling to look for manatee bones but no remains were found. We headed back out the lagoon and downriver. Near the mouth of the river 3-4 manatees were disturbed and these were followed for about 20 min to the bay at the San Pedro mouth. The San Pedro River is fed by a large watershed from the Lanier Swamp the major source of freshwater for the island for the entire region. We continued out the river and to the south about 2 km. Searching along the mangrove shoreline where the fishermen reported he had seen a manatee carcass two months prior, we found the skeletal remains of a juvenile individual. Skull, ribs, vertebrae and other bones were collected and returned to the boat. No tissue or skin was seen and we saw no evidence that it had been hunted (marks on the bones, for example). The number of sightings in the San Pedro River during this survey was dramatically higher than previous visits. The colder weather may have driven manatees from surrounding open water into the river to seek warm water at the scattered brackish springs and the warmer waters. The bottom water in the mangrove creeks is heated due to organic decomposition and then insulated from the effects of surface cooling by the freshwater lens (as observed in Florida). It appears that the San Pedro River and system is an extremely important habitat for manatees in the region as a source of freshwater, a warm water sanctuary and shelter. However, it appears that hunting remains a considerable problem in the area even though manatees are protected.
• January 14, 2010 Departed Colony Hotel at 6 AM for airport and left Isle of Youth at 8:30 AM for Havana. Arrived at 9:30 AM and proceeded to CIM to review data and photographs. It was decided that the next manatee necropsy and conservation workshop will be held the end of June 2010. CITMA/CNAP has agreed to send and pay expenses for 30 Cuban participants. The meeting will be held at Zapata Swamp. Figure 5 Our team, Gerardo Lastre Lopez, Dr. B. Powell, Dr. Jorge Angulo Valdez, Anmari Alvarez Aleman, Eddy Garcia Alfonso, Abelardo Dominguez and Lozaro Garcie Lopez.