285
Y. Sadovy de Mitcheson and P.L. Colin (eds.), Reef Fish Spawning Aggregations:
Biology, Research and Management, Fish & Fisheries Series 35,
DOI 10.1007/978-94-007-1980-4_9, © Springer Science+Business Media B.V. 2012
Abstract The scientifi c study and monitoring of spawning aggregations requires
fi eld and laboratory work using a wide variety of physical and biological methods;
but fi eld work, no matter the technological tools available, will remain of fundamental importance in studying aggregations particularly for future comparison. Methods
are becoming increasingly standardized allowing for meaningful comparison
between sites, times and species. Methods can be fi shery-dependent (gathering data
from captured fi shes) or -independent (observational, instrumental physical, interview data) within the subject areas of aggregation (1) discovery, (2) composition,
(3) dynamics, (4) life history parameters and (5) physical parameters. Methods for
each are summarized with selected subjects explored in more detail. Particularly
problematic areas for data gathering have been fi shery-independent determination
of numbers and/or sizes of fi shes and their distribution within aggregations and the
larger environment. GPS based methods of mapping aggregation location, extent
and fi sh density provide discrete snapshots of an aggregation, allowing visualization
of dynamics over days to years and are repeatable any time in the future by others.
Digital imaging (still and video) allows documentation previously impossible. Acoustic
tagging, particularly alongside conventional tagging, allows delineating spatial and
temporal aspects of aggregations. Hydroacoustic surveys are promising, but require
validation of data on species present, fi sh numbers and their sizes. Aggregation sites
should be instrumented to record physical data (e.g. temperature, currents, light) ideally
year round, rather than just during aggregation, to allow comparison of aggregation
periods with the entire year, and non-aggregation sites also evaluated for comparison
Detailed bathymetric mapping of sites is important and feasible and allows visualization
of geomorphology in relation to aggregations.
P. L. Colin (*)
Coral Reef Research Foundation , P.O. Box 1765, Palau 96940, Koror
email: crrf@palaunet.com
Chapter 9
Studying and Monitoring Aggregating Species
Patrick L. Colin
Y. Sadovy de Mitcheson and P.L. Colin (eds.), Reef Fish Spawning Aggregations:
Biology, Research and Management, Fish & Fisheries Series 35,
DOI 10.1007/978-94-007-1980-4_9, © Springer Science+Business Media B.V. 2012
Abstract The scientifi c study and monitoring of spawning aggregations requires
fi eld and laboratory work using a wide variety of physical and biological methods;
but fi eld work, no matter the technological tools available, will remain of fundamental importance in studying aggregations particularly for future comparison. Methods
are becoming increasingly standardized allowing for meaningful comparison
between sites, times and species. Methods can be fi shery-dependent (gathering data
from captured fi shes) or -independent (observational, instrumental physical, interview data) within the subject areas of aggregation (1) discovery, (2) composition,
(3) dynamics, (4) life history parameters and (5) physical parameters. Methods for
each are summarized with selected subjects explored in more detail. Particularly
problematic areas for data gathering have been fi shery-independent determination
of numbers and/or sizes of fi shes and their distribution within aggregations and the
larger environment. GPS based methods of mapping aggregation location, extent
and fi sh density provide discrete snapshots of an aggregation, allowing visualization
of dynamics over days to years and are repeatable any time in the future by others.
Digital imaging (still and video) allows documentation previously impossible. Acoustic
tagging, particularly alongside conventional tagging, allows delineating spatial and
temporal aspects of aggregations. Hydroacoustic surveys are promising, but require
validation of data on species present, fi sh numbers and their sizes. Aggregation sites
should be instrumented to record physical data (e.g. temperature, currents, light) ideally
year round, rather than just during aggregation, to allow comparison of aggregation
periods with the entire year, and non-aggregation sites also evaluated for comparison
Detailed bathymetric mapping of sites is important and feasible and allows visualization
of geomorphology in relation to aggregations.
P. L. Colin (*)
Coral Reef Research Foundation , P.O. Box 1765, Palau 96940, Koror
email: crrf@palaunet.com
Chapter 9
Studying and Monitoring Aggregating Species
Patrick L. Colin