Age, growth, and spawning season of red bream (Beryx decadactylus) off the southeastern United States Claudia Friess and George R. Sedberry SEDAR50-RD26 18 July 2016 20 Abstract—Red bream (Beryx deca- Age, growth, and spawning season dactylus) is a commercially important deep-sea benthopelagic fish with a cir- of red bream (Beryx decadactylus) cumglobal distribution on insular and continental slopes and seamounts. In off the southeastern United States the United States, small numbers are caught incidentally in the wreckfish Claudia Friess (contact author)1* (Polyprion americanus) fishery which 2 operates off the southeastern coast, George R. Sedberry but no biological information exists Email address for contact author: [email protected] for the management of the U.S. red 1 Grice Marine Laboratory bream population. For this study, oto- College of Charleston liths (n=163) and gonads (n=161) were 205 Fort Johnson Road collected from commercially caught Charleston, South Carolina 29412-9110 red bream between 2003 and 2008 * Present address: Ocean Conservancy to determine life history parameters. 106 E 6th St Specimens ranged in size from 410 Austin, TX 78701 to 630 mm fork length and were all determined to be mature by histo- 2 Gray’s Reef National Marine Sanctuary logical examination of the gonads. 10 Ocean Science Circle Females in spawning condition were Savannah, Georgia 31411 observed from June through Septem- ber, and reproductively active males were found year-round. Sectioned otoliths were difficult to interpret, but maximum age estimates were much higher than the 15 years pre- Red bream (Beryx decadactylus, Malha Bank and around the Ker- viously reported for this species from Cuvier, 1829) is one of three species guelen Islands. In the eastern North the eastern North Atlantic based on whole-otolith analysis. Estimated in the genus Beryx (Beryciformes: Atlantic, both alfonsino species are ages ranged from 8 to 69 years, and Berycidae). Similar to its congener, currently caught in a multispecies, a minimum lifespan of 49 years was the splendid alfonsino (B. splendens), multigear fishery that targets mainly validated by using bomb radiocarbon red bream have a circumglobal distri- blackspot seabream (Pagellus bogara- dating. Natural mortality was esti- bution in temperate to tropical waters veo) at depths of 200–600 m (ICES2). mated at 0.06/yr. This study shows and are commonly found on continen- In European waters alfonsinos are that red bream are longer lived and tal shelves and slopes, seamounts, and managed collectively because species- more vulnerable to overfishing than oceanic ridges at depths of at least specific landings data rarely exist. previously assumed and should be 1240 m (Busakhin, 1982). The third The status of the European stocks managed carefully to prevent over- species, B. mollis, is restricted to the is currently unknown owing to short exploitation. western North Pacific region and is catch time series, the lack of fishery- not further discussed in this article.1 independent data, and unreliable esti- Red bream and splendid alfonsino are mates of mortality rates, but there are commercially exploited wherever they reports of serial depletion of alfonsino occur in abundance, particularly in populations during the early years of the eastern North Atlantic around the rapidly expanding deep-sea fisher- the Macaronesian Islands (Large et ies on and around seamounts in the al., 2003); in the Pacific around New eastern North Atlantic (Vinnichenko, Caledonia (Lehodey et al., 1997), New 1997; ICES2). Zealand (Massey and Horn, 1990) In the western North Atlantic, al- and Japan (Adachi et al., 2000); fonsinos are caught incidentally off and in the Indian Ocean on Saya de the southeastern coast of the United States in the wreckfish (Polyprion 1 Because of the confusion created by americanus) fishery. The fishery op- regional differences in the use of common erates in an area of high topographic names for the Beryx species, the following relief known as the Charleston Bump, nomenclature will be used throughout located on the Blake Plateau south- Manuscript submitted 30 September 2009. the rest of this article: B. decadactylus Manuscript accepted 28 September 2010. will be referred to by its American Fish- Fish. Bull. 109:20–33 (2011). eries Society (AFS) common name “red 2 ICES (International Council for the bream” (Nelson et al., 2004; FAO common Exploration of the Sea). 2008. Report The views and opinions expressed name “alfonsino”), B. splendens by its of the working group on the biology or implied in this article are those of the FAO common name “splendid alfonsino” and assessment of deep-sea fisheries author (or authors) and do not necessarily (Froese and Pauly, 2008; AFS common resources, 3–10 March 2008, ICES Head- reflect the position of the National Marine name “alfonsino”), and the two collec- quarters, Copenhagen. ICES CM 2008/ Fisheries Service, NOAA. tively will be called “alfonsinos.” ACOM:14., 531 p. Friess and Sedberry: Age, growth, and spawning season for Beryx decadactylus 21 east of Charleston, South Carolina. The Charleston points. This information is needed if red bream become Bump is characterized by carbonate outcrops, scarps, a target for the fishery and need to be included in a scour depressions, and overhangs that are essential fishery management plan in the future. hard-bottom habitat for demersal fishes (Sedberry et al., 2001). In most global fisheries, splendid alfonsino is the most abundant Beryx species in the catch, but in the Materials and methods U.S. wreckfish fishery, red bream composes more than 95% of the alfonsino landings (senior author, personal Collection of samples observ.). Alfonsino landings in the United States are currently not monitored. Red bream landed by the commercial wreckfish fish- Life history data for red bream are sparse because ery operating on the Charleston Bump (approximately research on alfonsinos has focused almost exclusively 31°30′N, 79°W) were sampled from April 2003 to Janu- on the economically more important splendid alfonsino. ary 2008. All specimens were caught by vertical line A few studies have addressed both species, and it was fishing in depths of 450–600 m (Sedberry et al., 1999) concluded that distribution, feeding habits, reproductive and iced on the vessel until arrival at port. Every red parameters, age and growth, and larval development bream caught on a fishing trip was sampled during a port are similar (Busakhin, 1982; Mundy, 1990; Isidro, 1996; sampling trip. For each specimen, total length (TL), fork Dürr and Gonzalez, 2002). Alfonsinos are gonochoristic length (FL), and standard length (SL) were measured batch spawners (Isidro, 1996), their eggs and larvae are to the nearest millimeter, and total body weight (TBW) epipelagic, and juveniles are pelagic for several months was recorded in grams. Sagittal otoliths were extracted (Mundy, 1990) before moving into deeper waters and and stored dry in envelopes for age and growth analysis, assuming the adult benthopelagic lifestyle (Busakhin, and the entire gonad was removed and placed in 10% 1982; Lehodey et al., 1994). In the eastern North Atlan- buffered formalin for histological analysis. In addition, tic, female red bream reach sexual maturity at 276 mm otoliths and fork lengths from 22 small (FL≤400 mm) fork length. The maximum age estimate for the Azores specimens collected from the Azores were provided by red bream population is 15 years, although ages for this Gui Menezes of the Departamento de Oceanografia e species have never been validated (Isidro, 1996). Pescas (DOP), University of the Azores. These otoliths Basic biological information has not been published were examined to aid with aging technique development for the western North Atlantic red bream population. because initial counts of age increments for Charleston Many other deep-sea fishes have life history patterns Bump otoliths were much higher than ages previously characterized by slow growth, high longevity, and late reported for eastern North Atlantic red bream. maturity, all of which results in low productivity, high susceptibility to overfishing, and low resiliency (Merrett Age and growth and Haedrich, 1997; Koslow et al., 2000; Cheung et al., 2007). Knowledge of red bream life history traits is es- Sagittal otoliths were weighed to the nearest milligram, sential for establishing the biological reference points and either the right or left otolith (depending on the needed for management and, in the absence of tradi- condition of the otolith) was embedded in epoxy resin. A tional stock assessments, for conducting risk assess- Buehler Isomet low-speed saw (Buehler Ltd., Lake Bluff, ments to evaluate vulnerability and prevent overfishing IL) with a diamond wheel was used to cut transverse (Patrick et al., 2010). sections of approximately 0.6–0.7 mm thickness through The purpose of this study was to investigate the age, the focus. Sections were mounted on glass slides with growth, and reproductive biology of red bream caught Cytoseal mounting medium and viewed under a Nikon off the southeastern United States. We hypothesized SMZ-U dissecting scope (Nikon Instruments Inc., Mel- that red bream attain a much higher maximum age ville, NY) with transmitted and reflected light. than previously assumed, more similar to other deep- Exploratory readings were conducted along ventral water fishes that occur on the Charleston Bump, such and dorsal axes toward the proximal edge of the oto- as barrelfish (Hyperoglyphe perciformis) and blackbelly lith. Increments were counted independently by two rosefish (Helicolenus dactylopterus), which have estimat- readers, without knowledge of fish length or sex, and ed longevities of 85 and 30 years, respectively (White both readers rated the readability of otoliths. After the et al., 1998; Filer and Sedberry, 2008). Another goal of exploratory readings, the first reader made two counts the study was to validate high red bream age estimates (readings) over the period of several weeks to assess obtained through the interpretation of thin-sectioned within-reader precision, and the second reader made otoliths.