Coral Reefs (2008) 27:85–95 DOI 10.1007/s00338-007-0293-z REPORT A quantitative comparison of recreational spearWshing and lineWshing on the Great Barrier Reef: implications for management of multi-sector coral reef Wsheries A. J. Frisch · R. Baker · J-P. A. Hobbs · L. Nankervis Received: 3 May 2007 / Accepted: 6 August 2007 / Published online: 25 August 2007 © Springer-Verlag 2007 Abstract This study compared the catch composition, equitably across both Wshing sectors. A management strategy catch per unit eVort, and incidental impacts of spearWshers of this type will simplify enforcement of Wsheries regulations and lineWshers engaged in a structured Wshing program and avoid discrimination of particular Wshers in local whereby Wshing eVort was standardized across time, space communities where both Wshing methods are socially or and skill level. It was found that (1) the catch composition culturally important. of both groups of Wshers overlapped considerably, (2) the numbers of target Wsh caught by spearWshers (156) and Keywords SpearWshing · LineWshing · Catch per unit lineWshers (168) were not signiWcantly diVerent, (3) the eVort · Selectivity · Coral trout · Bycatch mean size of target Wsh caught by spearWshers (1.95 § 0.1 kg, §SE) was signiWcantly larger than the mean size of target Wsh caught by lineWshers (1.27 § 0.06 kg), and (4) spear- Introduction Wshers retained 43% more biomass of target species than did lineWshers (304 versus 213 kg, respectively). However, OverWshing is deemed to be one of the greatest threats to lineWshers used »1 kg of bait for every 3 kg of target Wsh the future of coral reefs (Jackson et al. 2001; Bellwood that were captured. LineWshers also caught far more under- et al. 2004; Newton et al. 2007). Understanding and manag- sized, undesirable, or protected Wshes (i.e., bycatch) and ing the eVects and yields of reef Wsheries is therefore cru- caused far more pollution (i.e., lost gear) than did spearWsh- cial for conserving coral reefs, and for bringing wealth and ers. It is concluded that the overall impacts of recreational stability to the tens of millions of people who use or depend spearWshing and lineWshing on Wshery resources of the on coral reefs as a source of food or income (Pauly et al. Great Barrier Reef are broadly equivalent (per unit of Wshing 2002; Newton et al. 2007). An important step in this direc- eVort), and that management regulations should be applied tion is to understand how various Wshing methods impact upon both target and non-target organisms. Two of the most common reef-Wshing methods used in Communicated by Environment Editor R. van Woesik. the Indo-PaciWc region are lineWshing, otherwise known as W A. J. Frisch (&) · R. Baker · J-P. A. Hobbs · L. Nankervis angling, and spear shing (Hundloe 1985; Wright and Rich- School of Marine and Tropical Biology, ards 1985; Dalzell et al. 1996; Pet-Soede et al. 2001; Cin- James Cook University, Townsville, QLD 4811, Australia ner and McClanahan 2006). LineWshing typically involves e-mail: [email protected] the use of a baited steel hook attached to a weighted nylon line. SpearWshing typically involves the use of a rubber- A. J. Frisch · J-P. A. Hobbs ARC Centre of Excellence for Coral Reef Studies, propelled spear, as well as associated dive gear such as James Cook University, Townsville, QLD 4811, Australia mask, snorkel and Wns. Although SCUBA is used in a few places, the vast majority of spearWshing is performed by Present Address: breath-hold divers (Dalzell et al. 1996; Gillett and Moy R. Baker NOAA Fisheries, SEFSC Galveston Laboratory, 2006). In most places, both lineWshing and spearWshing are Galveston, TX 77551, USA conducted from small (4 to 6 m), outboard-powered boats 123 86 Coral Reefs (2008) 27:85–95 with 1–5 Wshers per boat (Hundloe 1985; Wright and Rich- prevent meaningful, quantitative comparisons of spearWsh- ards 1985; Myers 1993; Dalzell et al. 1996). ing and lineWshing using available data. Even in developing nations, most reef Wshers have the The aim of this study, therefore, was to compare the option of either spearWshing or lineWshing, since both meth- catch composition, CPUE and incidental impacts of recrea- ods are relatively simple and require little capital invest- tional spearWshing and lineWshing in the context of a coral ment (Dalzell et al. 1996). In places where management reef Wshery. To do this, small teams of spearWshers and regulations exist (e.g., Australia), spearWshing and lineWsh- lineWshers were engaged in a program of structured Wshing ing tend to be managed uniformly (i.e., the same input and on the Great Barrier Reef (GBR), Queensland, Australia. output controls), mainly because of the lack of speciWc Importantly, both groups of Wshers participated concur- information pertaining to each Wshing method. However, it rently at the same reef site, thereby avoiding any spatial or is crucial for reef Wshery managers to acquire intimate temporal biases. Also, catch and eVort data were recorded knowledge of the selectivity, catch per unit eVort (CPUE) directly (i.e., “on site”) to maximize accuracy. and incidental impacts of both spearWshing and lineWshing. This is to enable formulation and implementation of Wshing regulations that (1) ensure target species are exploited on a Materials and methods sustainable basis, (2) encourage Wshing methods that mini- mize bycatch, habitat degradation, and Wshing-associated Field surveys pollution, and (3) allow shared Wshery resources to be allo- cated equitably among diVerent user groups (King 1995; Two teams of Wshers, one consisting of two lineWshers (one Walters and Martell 2004). Given the current concern over hook and line per person) and the other consisting of two the sustainability of reef Wsheries (Pauly et al. 2002; Bell- spearWshers (one spear or speargun per person; no SCUBA) wood et al. 2004; Newton et al. 2007), there are remarkably conducted normal Wshing activities aboard two small (4– few studies on the relative impacts of spearWshing and 6 m) boats (one team per boat). To standardize Wshing eVort lineWshing with respect to coral reef species (McClanahan among teams and over time, lineWshers and spearWshers and Mangi 2004). operated concurrently during synchronized “sessions” Because spearWshers choose the Wsh they shoot, this form which were 1.5 h in duration. A total of 45 sessions were of Wshing is regarded as highly selective, both in terms of conducted during twelve one-day “trips” (3–4 sessions per species and size (Dalzell 1996; Mann et al. 1997; Harper trip) that were spread across 14 months (May 2005 to July et al. 2000). One advantage of this selectivity is that 2006). Consecutive sessions during the same trip were sep- spearWshing has minimal impact on non-target species arated by a short recess (0.25–1 h) and all sessions were (Eckersley 1997). Another noteworthy characteristic of completed between 0800 and 1700 hours. Given that some breath-hold spearWshing is that it is limited to shallow water. locations may favor one or other Wshing method (Long Hence, the proportion of target Wshes available to spearWsh- 1957; Connell and Kingsford 1998), each session was con- ers is typically less than the proportion available to lineWsh- ducted at a diVerent site (i.e., an arbitrary area of coral reef ers (Mann et al. 1997). Despite this limitation, spearWshing that was approximately 1 km2). Sites were chosen haphaz- is often perceived to be more eYcient (in terms of CPUE) ardly and both teams Wshed the same site at the same time. than lineWshing (Long 1957; Eckersley 1997; Gillett and Sites were spread across seven coral reefs in the Townsville Moy 2006), although this is yet to be substantiated. The region of the GBR (Fig. 1) where local Wsh assemblages are range of previous estimates of CPUE for spearWshing and considered to be relatively intact (PandolW et al. 2003; Wil- lineWshing overlap considerably (Hundloe 1985; Wright and kinson 2004). For a complete description of the habitat, as Richards 1985; Dalzell 1996; Dalzell et al. 1996; Harper well as estimates of the distribution and abundance of target et al. 2000; Pet-Soede et al. 2001; McClanahan and Mangi Wsh species, see Done (1982) and Newman et al. (1997). To 2004). Furthermore, these estimates vary (within method) standardize access to reef habitats at each location, Wshing by at least an order of magnitude. This variability is proba- was restricted to depths of ·15 m (approximately the maxi- bly attributable to the fact that data were collected at diVer- mum working depth of most spearWshers). Since the focus ent times and places, using diVerent types of Wshers of this study was on reef Wshing, all participants were dis- (commercial, artisanal, subsistence or recreational). Addi- couraged from targeting pelagic species such as mackerel tionally, most of the data were collected indirectly, either by (F. Scombridae) and trevally (F. Carangidae). boat-ramp surveys, which tend not to accurately quantify Wshing eVort (Wright and Richards 1985), or by question- Sampling considerations naires and personal logbooks, techniques that are often biased and unreliable (Tarrant and Manfredo 1993; King Most popular food Wshes are non-uniformly distributed 1995; Connolly and Brown 1995). Together, these problems across small spatial scales (Newman et al. 1997; Connell 123 Coral Reefs (2008) 27:85–95 87 Data collection 145o E N Britomart Rf The identity, size, number and fate of all captured Wsh were Walker Rf Trunk Rf recorded shortly after capture (n.b. a Wsh was deWned as any Bramble Rf vagile Wshery resource, including WnWsh, crustaceans and cephalopods). Where possible, Wsh were identiWed to spe- Curacoa Is. Palm Is. cies level according to Randall et al. (1990) or Jones and Morgan (1994). Some of the less abundant species were Barber Is.