radiation experiment, five urchins died after 48 h of recovery, three in the
unprotected group and two in the protected group.
The second mass mortality event of echinoderms in Puerto Rico was between
1983 and 1984. Lessios (1995) stated that the 1983–1984 mass mortality of D.
antillarum was the most extensive and severe die-off ever recorded for a marine
invertebrate. Before 1983, the presence of this species was common (22 ind m
-2 )
on coral reefs (Lessios 1995). After the massive die-off, populations were drastically reduced by 95–100 % in many Caribbean locations (Lessios 1995). It was
theorized that a water-borne pathogen transported by surface currents was the main
cause of this mass mortality (Lessios et al. 1984, Phinney et al. 2001). In addition,
one report states that ballast water from ships was also linked with the spread of
the urchin-killing pathogen (Bak et al. 1984). The spread of the massive mortality
is believed to have originated from Punta Galeta, Panama and proceeded in two
different fronts. The first front went east from Panama to Tobago. The second front
was faster and went east of Costa Rica, North of Cayman Island, Belize, Mexico,
Jamaica, Gulf of Mexico, Florida, and to Bermuda. In February of 1984, an area of
3.5 million square kilometers was affected by this mass mortality (Lessios 1988).
Vicente and Goenaga 1984 observed the first diseased D. antillarum in January
1984 at Laurel reef, La Parguera, Puerto Rico. Before the mass mortality, densities
were reported from 2.6 ind m
-2 (Jobos Bay) to as high as 13.8 ind m
-2 (San Juan).
In Guayanilla densities before the mass mortality were 3.0 ind m
-2 and after were
as low as 0.13 ind m
-2 (Vincent et al. 1985).
Bunkley-Williams et al. (1986) reported the third recognized mass mortality of
echinoderms in Puerto Rico waters. This study described the isolated mortalities of
two sea urchins, Astropyga magnifica and Eucidaris tribuloides, during the winter
of 1984–1985 in the Northwest coast of Puerto Rico. An aggregation of 68
A. magnifica, at depths between 0.6 and 1.2 m deep with dropping spines and
rolling in the waves with the surge were observed at Crashboat Beach, Aguadilla
on December 8 and 12, 1984. These signs seemed very similar to those witnessed
during the D. antillarum 1983–84 die-off. Astropyga pulvinata (Lamarck) located
in deeper waters seemed healthy and there was an absence of sediment on tests. No
other species in the vicinity showed signs of disease or stress. Therefore, pollutants
were not thought to be a factor in this urchin mortality. In January 1985, there was
another mass mortality of E. tribuloides at Survival Beach near old Ramey Air
Force Base, Aguadilla. Six thousand to 8,000 sea urchins were observed washed
up on the beach. These die-offs were during times of rough waves and stormy
winter weather. No further mortalities were witnessed. These two mass mortalities
of A. magnifica and E. tribuloides are unexplained events.
Williams (1991) reported mass mortality outbreaks of T. ventricosus in Puerto
Rico between January and February 1995. The new die offs progressed more
slowly (6–8 days) compared to the D. antillarum die-off during 1983–84
(3–4 days). One thousand T. ventricosus were found dead at La Parguera
(Williams et al. 1996). This mortality was not localized but island wide. They also
witnessed urchins dying near Humacao and Fajardo. No samples were taken or
preserved. There was variation in symptoms. Many urchins were floating near the
14 Review of Echinoderm Research in Puerto Rico
463
unprotected group and two in the protected group.
The second mass mortality event of echinoderms in Puerto Rico was between
1983 and 1984. Lessios (1995) stated that the 1983–1984 mass mortality of D.
antillarum was the most extensive and severe die-off ever recorded for a marine
invertebrate. Before 1983, the presence of this species was common (22 ind m
-2 )
on coral reefs (Lessios 1995). After the massive die-off, populations were drastically reduced by 95–100 % in many Caribbean locations (Lessios 1995). It was
theorized that a water-borne pathogen transported by surface currents was the main
cause of this mass mortality (Lessios et al. 1984, Phinney et al. 2001). In addition,
one report states that ballast water from ships was also linked with the spread of
the urchin-killing pathogen (Bak et al. 1984). The spread of the massive mortality
is believed to have originated from Punta Galeta, Panama and proceeded in two
different fronts. The first front went east from Panama to Tobago. The second front
was faster and went east of Costa Rica, North of Cayman Island, Belize, Mexico,
Jamaica, Gulf of Mexico, Florida, and to Bermuda. In February of 1984, an area of
3.5 million square kilometers was affected by this mass mortality (Lessios 1988).
Vicente and Goenaga 1984 observed the first diseased D. antillarum in January
1984 at Laurel reef, La Parguera, Puerto Rico. Before the mass mortality, densities
were reported from 2.6 ind m
-2 (Jobos Bay) to as high as 13.8 ind m
-2 (San Juan).
In Guayanilla densities before the mass mortality were 3.0 ind m
-2 and after were
as low as 0.13 ind m
-2 (Vincent et al. 1985).
Bunkley-Williams et al. (1986) reported the third recognized mass mortality of
echinoderms in Puerto Rico waters. This study described the isolated mortalities of
two sea urchins, Astropyga magnifica and Eucidaris tribuloides, during the winter
of 1984–1985 in the Northwest coast of Puerto Rico. An aggregation of 68
A. magnifica, at depths between 0.6 and 1.2 m deep with dropping spines and
rolling in the waves with the surge were observed at Crashboat Beach, Aguadilla
on December 8 and 12, 1984. These signs seemed very similar to those witnessed
during the D. antillarum 1983–84 die-off. Astropyga pulvinata (Lamarck) located
in deeper waters seemed healthy and there was an absence of sediment on tests. No
other species in the vicinity showed signs of disease or stress. Therefore, pollutants
were not thought to be a factor in this urchin mortality. In January 1985, there was
another mass mortality of E. tribuloides at Survival Beach near old Ramey Air
Force Base, Aguadilla. Six thousand to 8,000 sea urchins were observed washed
up on the beach. These die-offs were during times of rough waves and stormy
winter weather. No further mortalities were witnessed. These two mass mortalities
of A. magnifica and E. tribuloides are unexplained events.
Williams (1991) reported mass mortality outbreaks of T. ventricosus in Puerto
Rico between January and February 1995. The new die offs progressed more
slowly (6–8 days) compared to the D. antillarum die-off during 1983–84
(3–4 days). One thousand T. ventricosus were found dead at La Parguera
(Williams et al. 1996). This mortality was not localized but island wide. They also
witnessed urchins dying near Humacao and Fajardo. No samples were taken or
preserved. There was variation in symptoms. Many urchins were floating near the
14 Review of Echinoderm Research in Puerto Rico
463