27
2 Ecosystem Aspects of Species That Aggregate to Spawn
2.2.1 Catchment Area
At the largest spatial scale (100 to > 1,000 km
2 ) the catchment area encompasses the
sum of home ranges and migration routes of a local spawning population that uses
a specifi c aggregation site during the annual reproductive cycle (Figs. 2.1 and 2.3 ).
The tagging methods briefl y described above are useful for measuring migration
distances and calculating catchment areas for FSA sites, as well as for identifying
the minimum management area of a spawning population. However, migration distances and therefore catchment areas can vary greatly depending upon a number of
factors. Based on limited data, the migration distance and catchment areas within a
family seem to be positively correlated with fi sh size (Chap. 4 ) and also area of reef
platform. For example, larger species, such as the Nassau grouper , reach maturity at
48 cm and maximum size at 94 cm or greater (Ault et al. 2008 ) and can migrate 110
to at least 240 km (Colin 1992 ; Carter et al. 1994 ) . Nassau grouper can have catchment areas estimated at 7,500 km
2 in locations with extensive reef systems such as
the Mesoamerican reef and the Bahamian archipelago (Nemeth 2009 ) . On the other
hand, on small isolated islands with deep water barriers such as the Cayman Islands
and Glover’s Reef, Belize, the migration distances of adult Nassau grouper may be
limited to 15–70 km, with estimated catchment area of 30–100 km
2 , depending
upon the shelf area surrounding each island (Colin et al. 1987 ; Semmens et al. 2005 ;
Starr et al. 2007 ) . Smaller species like the red hind, E. guttatus , which reach maturity at 25 cm TL and maximum size at 76 cm TL (Heemstra and Randall 1993 ; Ault
et al. 2008 ) , have smaller catchment areas estimated to range from 90 km
2 to 500
km
2 for migration distances of 16 km to 30 km, respectively, depending upon the
Fig. 2.3 Spatial scales of movement associated with aggregations of group-spawning species (e.g.
species that do not defend spawning territories and spawn in mid-water) showing the functional
migration area and the four spatio-temporal phases of the reproductive cycle. Spatial scales include
the catchment area, staging area, courtship arena and spawning aggregation site
2 Ecosystem Aspects of Species That Aggregate to Spawn
2.2.1 Catchment Area
At the largest spatial scale (100 to > 1,000 km
2 ) the catchment area encompasses the
sum of home ranges and migration routes of a local spawning population that uses
a specifi c aggregation site during the annual reproductive cycle (Figs. 2.1 and 2.3 ).
The tagging methods briefl y described above are useful for measuring migration
distances and calculating catchment areas for FSA sites, as well as for identifying
the minimum management area of a spawning population. However, migration distances and therefore catchment areas can vary greatly depending upon a number of
factors. Based on limited data, the migration distance and catchment areas within a
family seem to be positively correlated with fi sh size (Chap. 4 ) and also area of reef
platform. For example, larger species, such as the Nassau grouper , reach maturity at
48 cm and maximum size at 94 cm or greater (Ault et al. 2008 ) and can migrate 110
to at least 240 km (Colin 1992 ; Carter et al. 1994 ) . Nassau grouper can have catchment areas estimated at 7,500 km
2 in locations with extensive reef systems such as
the Mesoamerican reef and the Bahamian archipelago (Nemeth 2009 ) . On the other
hand, on small isolated islands with deep water barriers such as the Cayman Islands
and Glover’s Reef, Belize, the migration distances of adult Nassau grouper may be
limited to 15–70 km, with estimated catchment area of 30–100 km
2 , depending
upon the shelf area surrounding each island (Colin et al. 1987 ; Semmens et al. 2005 ;
Starr et al. 2007 ) . Smaller species like the red hind, E. guttatus , which reach maturity at 25 cm TL and maximum size at 76 cm TL (Heemstra and Randall 1993 ; Ault
et al. 2008 ) , have smaller catchment areas estimated to range from 90 km
2 to 500
km
2 for migration distances of 16 km to 30 km, respectively, depending upon the
Fig. 2.3 Spatial scales of movement associated with aggregations of group-spawning species (e.g.
species that do not defend spawning territories and spawn in mid-water) showing the functional
migration area and the four spatio-temporal phases of the reproductive cycle. Spatial scales include
the catchment area, staging area, courtship arena and spawning aggregation site