Download BINCKE: a highly efficient net for collecting reef fishes

Environmental Biology of Fishes 51: 111–115, 1998.
 1998 Kluwer Academic Publishers. Printed in the Netherlands.
BINCKE: a highly efficient net for collecting reef fishes
Todd W. Anderson1 & Mark H. Carr2,3
Present address: Department of Zoology, Oregon State University, Corvallis, OR 97331-2914, U.S.A.
2
Present address: Department of Biology, University of California, Santa Cruz, CA 95064, U.S.A.
3
Correspondence to M.H. Carr (e-mail: carr6biology.ucsc.edu)
1
Received 2.11.1996
Accepted 1.3.1997
Key words: coral reefs, fish collection, kelp forests, methods, SCUBA, structurally complex environments
Synopsis
The efficient collection of fishes from structurally complex environments (e.g., coral reefs, kelp forests) is
difficult because conventional collecting methods generally cannot be used and many of the fishes are mobile
and active. We describe the design, operation, and application of a diver-propelled net for efficiently collecting many species of benthic fish that reside on coral reefs and on kelp-forested rocky reefs. The overall size of
the net and mesh size of the netting can be adjusted according to the size and behavior of targeted species to
minimize drag and damage to specimens. Altering these dimensions combined with proper use of the net can
result in a high rate of capture success.
Introduction
Collecting organisms from their natural habitats is
critical to a variety of studies ranging from systematics and genetics to physiology and ecology. For
reef fishes, advances in such studies have been hindered by the difficulty in efficiently collecting live,
undamaged specimens from structurally complex
environments. For example, the increasing interest
in recruitment of early life stages to local fish populations has prompted the need to collect small, elusive, and sometimes cryptic individuals. Various
collecting methods have been developed, most of
which are time-consuming and labor-intensive;
these include hand nets, traps, drop nets, and the
use of anesthetics (Coyer & Witman 1990). To efficiently collect large numbers of fishes associated
with structural features (e.g., corals, macroalgae) of
reef habitats, we have developed a net specifically
designed for use with SCUBA. This net was initially
developed to collect recently settled rockfishes
(Scorpaenidae) from kelp-forested rocky reefs for
taxonomic (Anderson 1983), diet (Singer 1985), and
recruitment (Carr 1991) studies. Subsequently, it
has proven useful for collecting all life intervals of
several species from temperate (Carr 1989, 1994,
Anderson 1994, Anderson & Sabado 1995, Behrents-Hartney 1997) and tropical (Carr & Hixon
1995, Forrester unpublished, Hixon & Carr unpublished) regions. It is particularly effective for collecting species that aggregate in the water column
adjacent to structure, but less effective for solitary
cryptic species that maintain contact with the substratum. Because of its wide success in collecting
fishes on both coral reef and kelp-forested rocky
reefs, this net is referred to as the Benthic Ichthyofauna Net for Coral/Kelp Environments
(BINCKE). Although the BINCKE is not the first
diver-operated net for collecting small reef fishes
(e.g., McCleneghan & Houk 1978), its ease of oper-
Please indicate author’s corrections in blue, setting errors in red
136196 EBFI
ART.NO 1735 (499)
ORD.NO 231499.Z
112
ation and versatility make it a significant improvement over previous designs. Here we describe the
design, operation, and application of the BINCKE.
Net design
The basic design of the BINCKE is a rectangular
net opened and closed by means of a rigid, hinged
frame at one end (Figure 1). The size of the
BINCKE, determined by the dimensions of the
frame (height and width) and length of the netting
(depth), should vary depending upon the size and
behavior of targeted species. The frame dimensions
and length of netting determine the gape of the net
and capture volume, respectively. Frame dimensions and length of netting increase for collection of
larger individuals or aggregations and for more actively swimming species. Typically, the rectangular
frame has a height-to-width ratio of 1 : 2 with height
ranging in size from 0.75 m to 1.0 m. Netting length
typically varies with frame height in a ratio of 1 : 3
(height to length). Drag (resistance to moving the
net through the water) increases substantially with
both frame size and netting length. Thus, collection
of more actively swimming species is made more
difficult with a larger BINCKE and the net’s dimen-
Figure 1. Design of the Benthic Ichthyofauna Net for Coral/Kelp
Environments (BINCKE). Illustration is to scale.
sions should be altered accordingly. Because mesh
size also influences drag, it may be necessary to alter
height-to-length ratios for different mesh sizes.
Square mesh size is critical for retention of specimens and as it influences drag. Smaller mesh sizes
are required for collecting small fishes and to minimize damage to specimens. However, drag is inversely related to mesh size such that capture success
declines with decreasing mesh size. Thus, optimal
mesh size is achieved by using the smallest mesh
size that will allow sufficient net speed to capture
fleeing fish. In addition, smaller mesh is more visible and therefore more easily avoided, especially
by actively swimming fishes. Because dark-colored
netting is less visible, greater capture success can be
achieved by dyeing the netting to a dark green, dark
blue, dark red or black color. Typically, square mesh
size (mm) ranges from a minimum of 1.5 mm for
collecting recently settled early juveniles, up to
25 mm for many adult reef fishes (Table 1).
Materials and construction
The frame is constructed from 12.5 mm outside diameter Schedule 40 polyvinyl chloride (PVC) pipe.
Holes (6 mm diameter) are drilled through the
walls of the pipe approximately every 20 cm along
the length of the frame to permit water to enter the
pipe and decrease frame buoyancy. The corners of
the frame consist of four PVC 90° elbows affixed to
the pipe with PVC primer and glue. The two halves
of the frame are connected with two 15 cm long sections of 12.5 mm inside diameter Tygon tubing that
fit tightly over the PVC frame ends and serve as
hinges to open and close the net.
Knotless nylon netting is used to minimize abrasion to captured fish; Regents, Ace, and Delta are
commonly used styles of netting. The netting is
comprised of two panels. The first panel is rectangular with short and long dimensions equal to the
net length and frame circumference, respectively. A
9 cm wide tube/fold is sewn along the edge of one of
the long sides, through which the PVC frame is inserted, preventing gaps between the frame and the
net through which fish might escape. The short sides
of the panel are sewn together as a seam (Figure 1)
Please indicate author’s corrections in blue, setting errors in red
136196 EBFI
ART.NO 1735 (499)
ORD.NO 231499.Z
113
Table 1. Appropriate net mesh size for size range of various reef fishes.
Family
Species
Standard length (mm)
Square mesh size in mm
Scorpaenidae
Serranidae
Sebastes spp.
Paralabrax clathratus
Embiotocidae
Brachyistius frenatus
Embiotoca jacksoni
Hexagrammos decagrammus
Clepticus parrai
Halichoeres pictus
Halichoeres garnoti
Halichoeres semicinctus
Thalassoma bifasciatum
Heterostichus rostratus
Chromis cyanea
Coryphopterus personatus
Coryphopterus glaucofraenum
Gnatholepis thompsoni
Ocyurus chrysurus
15–100
15–100
100–250
30–120
100–250
100–250
10–30
10–30
10–100
100–250
10–30
30–350
10–60
10–30
10–70
10–70
80–120
1.5–6.0
1.5–6.0
6.0–12.0
6.0
6.0–12.0
6.0–12.0
1.5
1.5
1.5–6.0
6.0–12.0
1.5
1.5–12.0
3.0
1.5
1.5–6.0
1.5–6.0
6.0
Hexagrammidae
Labridae
Clinidae
Pomacentridae
Gobiidae
Lutjanidae
to form the side-walls of the net. To enclose the net,
a second panel of dimensions the same as the frame
is sewn onto the back edge of the first panel. A
heavy polyester carpet thread is used for sewing the
tube and the panels of netting together.
Operation and applications
The BINCKE can be operated by one or two divers
depending on its size and method of collection. For
the collection of large aggregations of fishes, two
divers, one on either side of the BINCKE, encircle
the aggregation. This is best achieved when the fish
are bounded by physical structure (e.g., vertical
rock wall) restricting their direction of escape. Alternatively, for quickly moving species that reside
near the reef surface, one diver will hold the
BINCKE open while one or more other divers herd
fish towards and into the net. A single diver can
hold both sides of the frame and sweep the
BINCKE vertically towards the water surface or
the reef bottom; this again restricts the direction of
escape of fishes by using a physical barrier. Finally,
the net can be laid flat and open on the reef surface
and baited to attract large individuals of the target
species. As fish accumulate over the net to feed, the
two halves of the frame are raised to enclose them.
A closed BINCKE is easily transported by one diver back to a boat or to shore without escapement of
fish; captured fish can also be transferred from the
BINCKE to large plastic bags or mesh cylinders underwater to allow for more collecting before transport.
Specific examples of the application of this net
include the collection of several species in a variety
of families from several locations:
Temperate reef fishes
Juveniles
Sebastes spp. (Scorpaenidae), Paralabrax clathratus
(Serranidae) and Brachyistius frenatus (Embiotocidae) – Juvenile Sebastes spp. and P. clathratus (15–
100 mm standard length (SL)), and B. frenatus (30–
50 mm SL) were collected from kelp forests along
the coastal northeastern Pacific. Large aggregations of juvenile Sebastes spp. above the reef were
collected with a large (1 m × 2 m frame) BINCKE
by two divers. Single fish and small aggregations of
Sebastes spp., P. clathratus, and B. frenatus associated with large kelp plants (e.g., Macrocystis pyrifera and Laminaria spp.) were collected by one diver
Please indicate author’s corrections in blue, setting errors in red
136196 EBFI
ART.NO 1735 (499)
ORD.NO 231499.Z
114
sweeping a smaller (0.5 m × 1.0 m frame) BINCKE
along plants and upward toward the kelp surface canopy. Individuals or small aggregations near the
reef were collected by a single diver sweeping the
smaller BINCKE downward over the reef surface.
Large juveniles and adults
Brachyistius frenatus and Embiotoca jacksoni (Embiotocidae), Heterostichus rostratus (Clinidae),
Hexagrammos decagrammus (Hexagrammidae),
Halichoeres semicinctus (Labridae), and Paralabrax clathratus (Serranidae) – Large juvenile and
small adult B. frenatus (60–120 mm SL) and H. rostratus (50–350 mm SL) were collected from kelp
forests off southern California. Small to large aggregations of juveniles and solitary adults in the
kelp surface canopy were collected with a 0.5 m × 1
m frame BINCKE by one diver with an upward
sweeping movement initiated from 2–3 m below the
canopy. Large juvenile and small adult (100–
250 mm SL) H. decagrammus, E. jacksoni, H. semicinctus, and P. clathratus were collected from the
reef surface. H. decagrammus, H. semicinctus, and
P. clathratus were often collected using the baited
technique as described above.
Large juveniles and adults
Chromis cyanea (Pomacentridae), Coryphopterus
personatus, Coryphopterus glaucofraenum and
Gnatholepis thompsoni (Gobiidae) – Large juvenile C. cyanea (40–70 mm SL) and juvenile and
adult C. personatus (30 mm SL), C. glaucofraenum
and G. thompsoni (40–70 mm SL) were collected by
slowly herding fish into an open BINCKE flush
with coral or a sand bottom.
Acknowledgements
We thank V. Breda, G. Hoelzer, M.M. Perez, and M.
Singer for contributing to the initial development
and application of the BINCKE. J. Harding, M.
Hixon, D. Kalik, and S. Thompson provided helpful
comments in preparation of the manuscript. Support during manuscript preparation was provided
to M. Carr by NSF grant OCE-92-17163, the National Undersea Research Program (Caribbean Marine
Research Center), and Minerals Management Service grant 14-35-0001-30758, and T. Anderson was
supported by a Friday Harbor Laboratories Postdoctoral Fellowship, University of Washington.
Coral reef fishes
References cited
Juveniles
Chromis cyanea (Pomacentridae), Coryphopterus
personatus (Gobiidae), Clepticus parrai, Halichoeres garnoti, Halichoeres pictus and Thalassoma
bifasciatum (Labridae), and Ocyurus chrysurus
(Lutjanidae) – Juvenile and adult C. cyanea (10–
60 mm SL), C. personatus (10–30 mm SL), juvenile
C. parrai, H. pictus, and T. bifasciatum (10–30 mm
SL), and O. chrysurus (80–120 mm SL), were collected from both coral and artificial reefs in the Bahamas or U.S. Virgin Islands. Small to large aggregations (≤ 50 fish) of all five species were collected
by slowly herding fish into a BINCKE set at the
edge of a coral promontory.
Anderson, T.W. 1983. Identification and development of nearshore juvenile rockfishes (genus Sebastes) in central California kelp forests. Master’s Thesis, California State University,
Fresno. 216 pp.
Anderson, T.W. 1994. Role of macroalgal structure in the distribution and abundance of a temperate reef fish. Mar. Ecol.
Prog. Ser. 113: 279–290.
Anderson, T.W. & B.D. Sabado. 1995. Correspondence between
food availability and growth of a planktivorous temperate reef
fish. J. Exp. Mar. Biol. Ecol. 189: 65–76.
Behrents-Hartney, K. 1997. Site fidelity and homing behaviour
of some kelp bed fishes. J. Fish Biol. (in press).
Carr, M.H. 1989. Effects of macroalgal assemblages on the
recruitment of temperate zone fishes. J. Exp. Mar. Biol. Ecol.
126: 59–76.
Carr, M.H. 1991. Habitat selection and recruitment of an assemblage of temperate zone reef fishes. J. Exp. Mar. Biol. Ecol.
146: 113–137.
Carr, M.H. 1994. Effects of macroalgal dynamics on recruitment
of a temperate reef fish. Ecology 75: 1320–1333.
Carr, M.H. & M.A. Hixon. 1995. Predation effects on early post-
Please indicate author’s corrections in blue, setting errors in red
136196 EBFI
ART.NO 1735 (499)
ORD.NO 231499.Z
115
settlement survivorship of coral-reef fishes. Mar. Ecol. Prog.
Ser. 124: 31–42.
Coyer, J. & J. Witman. 1990. The underwater catalog: a guide to
methods in underwater research. Shoals Marine Laboratory,
Cornell University and New York Sea Grant Program, Ithaca.
72 pp.
McCleneghan, K. & J.L. Houk. 1978. A diver operated net for
catching large numbers of juvenile marine fishes. Calif. Fish
Game 64: 305–307.
Singer, M.M. 1985. Food habits of juvenile rockfishes (Sebastes)
in a central California kelp forest. U.S. Fish. Bull. 83: 531–541.
Please indicate author’s corrections in blue, setting errors in red
136196 EBFI
ART.NO 1735 (499)
ORD.NO 231499.Z