See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/272351030 Fish growth, reproduction, and tissue production on artificial reefs relative to natural reefs Article in ICES Journal of Marine Science · May 2014 DOI: 10.1093/icesjms/fsu082 CITATIONS READS 8 87 2 authors: Jennifer Granneman Mark Steele University of South Florida California State University, Northridge 3 PUBLICATIONS 14 CITATIONS 52 PUBLICATIONS 1,344 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Master's Thesis Project View project All content following this page was uploaded by Jennifer Granneman on 16 February 2015. The user has requested enhancement of the downloaded file. ICES Journal of Marine Science Advance Access published May 23, 2014 ICES Journal of Marine Science ICES Journal of Marine Science; doi:10.1093/icesjms/fsu082 Fish growth, reproduction, and tissue production on artificial reefs relative to natural reefs Jennifer E. Granneman*‡ and Mark A. Steele Department of Biology, California State University, 18111 Nordhoff St., Northridge, CA 91330-8303, USA Downloaded from *Corresponding author: tel: +1 727 452 0127; fax: +1 727 553 1189; e-mail: [email protected] ‡Present address: College of Marine Science, University of South Florida, 140 7th Ave. South, St Petersburg, FL 33701, USA Granneman, J. E., and Steele, M. A. Fish growth, reproduction, and tissue production on artificial reefs relative to natural reefs. – ICES Journal of Marine Science, doi: 10.1093/icesjms/fsu082. http://icesjms.oxfordjournals.org/ Received 12 January 2014; revised 1 April 2014; accepted 13 April 2014. The extent to which artificial reefs may be useful for mitigation of environmental impacts, fisheries management, and conservation depends in part upon how well the organisms that live on them fare. We tested whether fish living on artificial reefs were in similar condition (weight-at-length), grew, foraged, reproduced, and produced tissue at rates similar to those on natural reefs. We studied five artificial–natural reef pairs spread over .200 km in the Southern California Bight. Underwater visual transects were used to quantify density and size structure of four target species (Paralabrax clathratus, Paralabrax nebulifer, Semicossyphus pulcher, and Embiotoca jacksoni), which were also collected to measure foraging success, condition, growth, reproductive output, and tissue production. Generally, fish living on artificial reefs fared as well or better than those on natural reefs, with some exceptions. Semicossyphus pulcher fared better on artificial reefs, having higher foraging success, fecundity, densities, and tissue production. Embiotoca jacksoni grew faster on natural reefs, and P. nebulifer was in slightly better condition on natural reefs. Total fish at University of South Florida on June 7, 2014 tissue production tended to be higheron artificial reefsthan on natural reefs, though this pattern was not evident on all reef pairs. Tissue production was positively correlated with the abundance of large boulders, which was higher on artificial reefs than natural reefs. The similar or greater pro- duction of fish tissue per cubic metre on artificial reefs relative to natural reefs indicates that these artificial habitats are valuable in producing fish biomass. Fish living on artificial reefs fared as well as those living on natural reefs, indicating that well-designed artificial reefs can be useful tools for mitigation, conservation, and fisheries management. Keywords: artificial reefs, condition, growth, habitat, mitigation, population density, reef fish, reproduction, tissue production, Southern California Bight. Introduction organisms be similar to those on natural reefs, but demographic Artificial reefs are widely used, and for some purposes, such as miti- rates such as growth, reproductive output, and mortality must gating environmental impacts (Hueckel et al., 1989; Ambrose, also be similar. These rates have seldom been compared between 1994), these reefs must function similarly to natural reefs. Most artificial and natural reefs, and the few studies that have made studies that evaluate how well artificial reefs work do so by compar- such comparisons have evaluated a single demographic rate in a ing the density or assemblage structure of organisms on these reefs single species (e.g. growth: Love et al., 2007; La Mesa et al., 2010) relative to natural reefs. While such studies provide valuable infor- or on single artificial reefs (e.g. DeMartini et al., 1994; Johnson mation, they cannot answer key questions about how well artificial et al., 1994). Replicated comparisons of several artificial and reefs function. Despite similar densities and identities of organisms natural reefs are necessary to evaluate the functioning of artificial living on artificial and natural reefs, artificial reefs could be demo- reefs (Carr and Hixon, 1997). graphic sinks that do not contribute to or may even reduce regional Here, we compare growth, condition, foraging success, repro- production of marine organisms (Polovina, 1989; Bohnsack et al., ductive potential, density, and tissue production of fish on five 1997; Pickering and Whitmarsh, 1997; Osenberg et al., 2002; large artificial reefs with those on five paired natural reefs. We Powers et al., 2003). studied four ecologically and economically important fish species For artificial reefs to benefit marine organisms by increasing re- on reefs in the Southern California Bight. By studying multiple gional production, not only must densities of resident marine species on several reefs, we were able to evaluate the generality of # International Council for the Exploration of the Sea 2014. All rights reserved. For Permissions, please email: [email protected] Page 2 of 11 J. E. Granneman and M. A. Steele any differences between artificial and natural reefs, and evaluate Each fish was weighed, total length measured, and the sagittal which attributes of reefs were associated with any differences otoliths, gonads, and digestive tracts were removed and stored. between the two reef types. To our knowledge, this study is the Before storage, gonads were examined macroscopically to deter- first to compare reproductive potential and tissue production on mine sex and stage of maturity, and were classified as follows: F1 artificial and natural reefs. (immature female), F2 (inactive mature female), F3 (active mature female), F4 (ripe mature female), F5 (hydrated female), Methods M1 (immature/inactive male), M2 (active mature male), and M3 Study sites and study species (ripe flowing male). This study was conducted between June and August 2009 on ten Fish growth and condition reefs that spanned 225 km of coastline within the Southern Somatic growth over the year before collection was estimated by California Bight. Five artificial reefs and the five natural reefs otolith back-calculation (details in Granneman, 2011). We limited closest to them were sampled. The artificial reefs studied were our growth estimate to only the preceding year to maximize the Topanga, Wheeler J. North, Pendleton, Torrey Pines 2, and Pacific likelihood that the fish collected had resided on the reef they were Beach. These artificial reefs spanned a broad range of sizes collected from for the whole duration of the growth increment. (924–704 000 m2; median ¼ 5600 m2), ages (10–34 year), relief Based on what is known about the movement patterns of the four Downloaded from (,1–4.9 m), and configurations (1–74 modules); but they were study species (Hixon, 1981; Lowe et al., 2003; Topping et al., 2005; all composed primarily of quarry rock (the Wheeler J. North reef Mason and Lowe, 2010), we think it is likely that the vast major- had a small proportion of concrete). The natural reefs surveyed ity of the fish collected had resided on the reef they were collected were large, contiguous reefs (87 700–11 333 000 m2; median ¼ 3 from for the whole duration of the growth increment. Back- 512 000 m2) with low relief (,1 m). The average reef depth calculation of growth was possible because the otoliths had annual ranged from 7 to 16 m, with pairs having no more than a 2.3 m http://icesjms.oxfordjournals.org/ rings (Love et al., 1996; Baca-Hovey et al., 2002; Froeschke et al., ¼ depth difference (median difference 0.5 m). Artificial and 2007) and there is a tight relationship between otolith size and , natural reef pairs were 7.5 km apart and thus experienced body size in the study species (JEG, unpublished data). We deter- similar oceanographic conditions. mined the equations defining the linear relationship between fish We studied four fish species: kelp bass (Paralabrax clathratus), total length and otolith radius for each species. These equations barred sand bass (Paralabrax nebulifer), California sheephead were calculated after excluding outliers outside of 95% confidence (Semicossyphus pulcher), and black perch (Embiotoca jacksoni). intervals. The relationship between fish weight and total length These species are some of the most abundant, and ecologically for each species was used to calculate weight change during the and economically important nearshore species inhabiting the preceding year. The estimates of fish growth obtained from otolith rocky reefs of Southern California (Cowen, 1983; Tegner and back-calculation should be interpreted with some caution given at University of South Florida on June 7, 2014 Dayton, 2000; Erisman et al., 2011). Kelp bass and barred sand that otolith growth is an