ASSESSING SHARK AND RAY BYCATCH IN INDONESIAN DEEPWATER SNAPPER-GROUPER FISHERIES FINAL REPORT Prepared for The Nature Conservancy Indonesia by Vanessa Jaiteh, Coral Reef Research Foundation February 2017 ASSESSING SHARK BYCATCH IN INDONESIAN DEEP-­‐SLOPE SNAPPER-­‐GROUPER FISHERIES TABLE OF CONTENTS 1. Background and Objectives .................................................................................... 3 2. CODRS Image Analysis ........................................................................................... 3 Summary .................................................................................................................. 3 Species composition ................................................................................................ 5 Geographic distribution of shark bycatch .............................................................. 11 Occurrence of recent pups and juvenile sharks ..................................................... 15 3. Species of Concern ............................................................................................... 15 4. Recommendations for monitoring shark bycatch ................................................. 16 Consistent recording of shark and ray bycatch ...................................................... 16 Image composition ................................................................................................ 18 5. Conclusions ........................................................................................................... 20 2 ASSESSING SHARK BYCATCH IN INDONESIAN DEEP-­‐SLOPE SNAPPER-­‐GROUPER FISHERIES 1. BACKGROUND AND OBJECTIVES Fisheries certification schemes, such as the Marine Stewardship Council (MSC), are gaining popularity as a means of promoting seafood sustainability and food security, and meeting an increasing global demand for sustainably sourced seafood. As one of the world’s leading seafood producers, Indonesia has struggled to achieve seafood certification in many of its fisheries, but recent national developments have sparked increased efforts to this end. Shark and ray (hereafter referred to as ‘shark’) bycatch is a particular challenge to MSC and other certification schemes due to the relatively recent, but in some cases severe, declines in a number of shark populations as a result of their capture in target fisheries and as bycatch. Since 2014, The Nature Conservancy (TNC) is working towards MSC certification with a number of Indonesian deep-slope (50-500m) dropline and demersal longline fisheries that target various snapper, grouper and emperor species. With homeports and fishing grounds in many parts of central and eastern Indonesia, the catch of sharks is likely to vary by species, geographic region, fishing gear, and depth. Shark bycatch and its mitigation is an essential consideration in the MSC certification process. The purpose of this work was therefore to identify the shark and ray species caught in Indonesian deep- slope fisheries and to provide advice on how to routinely monitor shark bycatch. This was achieved using images of the catch recorded by captains onboard fishing vessels as part of the Captain Operated Data Recording System (CODRS). Images in the CODRS were also used to develop a species check list and species identification aids, as well as an illustrated instruction sheet for captains on best practices in taking photos to aid species identification. 2. CODRS IMAGE ANALYSIS SUMMARY Twenty-seven vessels submitted a total of 153 photographs of sharks and rays to CODRS. Photographs were taken on 81 days between 17th October 2015 and 29th 3 ASSESSING SHARK BYCATCH IN INDONESIAN DEEP-­‐SLOPE SNAPPER-­‐GROUPER FISHERIES October 2016. From 248 individuals that were recognized on these images, 12 were cobias (i.e. shark look-alike teleost fish), and at least 29 individuals, possibly more, were photographed more than once. Although this means that a definite total count of individuals is not possible, an estimated 207 were distinct individuals that belonged to at least 36 species and 18 families (see species list in Table 1 below). Table 1. List of shark and ray species recorded from CODRS images Family Genus Species Common name Carcharhinidae Carcharhinus albimarginatus Silvertip shark Carcharhinidae Carcharhinus altimus Bignose shark Carcharhinidae Carcharhinus amblyrhynchoides Graceful shark Carcharhinidae Carcharhinus amblyrhynchos Grey reef shark Carcharhinidae Carcharhinus amboinensis Pigeye shark Carcharhinidae Carcharhinus falciformis Silky shark Carcharhinidae Carcharhinus limbatus Blacktip shark Carcharhinidae Carcharhinus obscurus Dusky whaler Carcharhinidae Carcharhinus plumbeus Sandbar shark Carcharhinidae Carcharhinus sorrah Spot-tail shark Carcharhinidae Galeocerdo cuvier Tiger shark Carcharhinidae Loxodon macrorhinus Sliteye shark Carcharhinidae Negaprion acutidens Lemon shark Carcharhinidae Rhizoprionodon acutus Milk shark Carcharhinidae Rhizoprionodon oligolinx Grey sharpnose shark Carcharhinidae Triaenodon obesus Whitetip reef shark Carcharhinidae Carcharhinus sp. Whaler shark Centrophoridae Centrophorus sp. Gulper shark Dasyatidae Himantura uarnak Reticulate whipray Ginglymostomatidae Nebrius ferrugineus Tawny nurse shark Hemigaleidae Hemipristis elongata Fossil shark Hemiscyllidae Chiloscyllium punctatum Brownbanded bambooshark Hexanchidae Hexanchus nakamurai Bigeye sixgill shark Lamnidae Isurus oxyrinchus Shortfin mako Myliobatidae Aetobatus narinari Spotted eagle ray Orectolobidae Orectolobus ornatus Indo wobbegong Orectolobidae Orectolobus sp. Wobbegong shark Rhincodontidae Rhincodon typus Whale shark (not captured) 4 ASSESSING SHARK BYCATCH IN INDONESIAN DEEP-­‐SLOPE SNAPPER-­‐GROUPER FISHERIES Family Genus Species Common name Rhinidae Rhina ancylostoma Shark ray Rhinobatidae Rhinobatos sp. Shovelnose ray Rhynchobatidae Rhynchobatus australiae Whitespotted guitafish Rhynchobatidae Rhynchobatus laevis Smoothnose wedgefish Sphyrnidae Sphyrna lewini Scalloped hammerhead Sphyrnidae Sphyrna mokarran Great hammerhead Squalidae Squalus sp. Spurdog shark Stegostomatidae Stegostoma fasciatum Leopard shark Triakidae Hemitriakis sp. Houndshark SPECIES COMPOSITION The shark bycatch was dominated by Carcharhinids, also known as requiem or whaler sharks, which made up 56% of the catch (n= 110, Figure 1). A further 11% and 9% of the catch was made up of hammerhead sharks (Sphyrnidae, n= 22), mainly of the species Sphyrna lewini (scalloped hammerhead) and guitarfish (family Rhynchobatidae, n= 17), most of which were whitespotted guitarfish, Rhynchobatos australiae. The remaining 15 families contributed 5% or less to the total catch (Figure 1). Finally, 12 individuals mistakenly assigned to the CODRS shark images database were cobia (Rachycentron canadum, family Rachycentridae). Although shark look- alikes, they are teleost fish with rays in their fins. 5 ASSESSING SHARK BYCATCH IN INDONESIAN DEEP-­‐SLOPE SNAPPER-­‐GROUPER FISHERIES Carcharhinidae Sphyrnidae Rhynchobatidae Centrophoridae Rhinidae Hemiscyllidae Triakidae Squalidae Orectolobidae Lamnidae Family Stegostomatidae Rhinobatidae Hexanchidae Dasyatidae Rhincodontidae Myliobatidae Hemigaleidae Ginglymostomatidae 0% 10% 20% 30% 40% 50% 60% Percentage in catch Figure 1. Proportion of individuals from each identified taxonomic family that made up the shark and ray bycatch recorded in the central and eastern Indonesian deep- slope snapper and grouper fishery. In terms of individual species, the spot-tail shark Carcharhinus sorrah was the most abundant (n = 28), followed by the scalloped hammerhead shark Sphyrna lewini (n = 21, Figure 2). Tiger sharks, whitespotted guitarfish, silvertips and gulper sharks were all represented by at least 10 individuals. Other, less abundant species included two reticulate whiprays (Himantura uarnak), an eagle ray (Aetobatus narinari), a tawny nurse shark (Nebrius ferrugineus), two wobbegong sharks (Orectolobus sp.) and a fossil shark (Hemipristis elongata, Figure 2). The latter was only recently described as occurring in eastern Indonesia; previously its range was thought to extend only to the eastern coast of Java. This CODRS record of a fossil shark provides further evidence of the presence of this species in central and eastern Indonesia, and highlights the usefulness of fisher-contributed data to the advancement of scientific knowledge. 6 ASSESSING SHARK BYCATCH IN INDONESIAN DEEP-­‐SLOPE SNAPPER-­‐GROUPER FISHERIES Carcharhinus sorrah Sphyrna lewini Galeocerdo cuvier Unidentified Rhynchobatus australie Carcharhinus albimarginatus Centrophorus sp. Carcharhinus amblyrhynchos Carcharhinus amboinensis Carcharhinus sp. Rhizoprionodon acutus Rhina ancylostoma Chiloscyllium punctatum Rhynchobatus laevis Loxodon macrorhinus Carcharhinus limbatus Squalus sp. Rhizoprionodon acutus Hemitriakis sp. Carcharhinus plumbeus Stegostoma fasciatum Species Orectolobus cf ornatus Negaprion acutidens Hexanchus nakamurai Carcharhinus obscurus Himantura uarnak Isurus oxyrinchus Triaenodon obesus Sphyrna mokarran Rhizoprionodon oligolinx Rhinobatos sp. Rhincodon typus Orectolobus sp. Nebrius ferrugineus Hemipristis elongata Carcharhinus melanopterus Carcharhinus falciformis Carcharhinus amblyrhynchoides Carcharhinus altimus Aetobatus narinari 0 5 10 15 20 25 30 Number of individuals Figure 2. The number of individuals of each species recorded from CODRS images 7 ASSESSING SHARK BYCATCH IN INDONESIAN DEEP-­‐SLOPE SNAPPER-­‐GROUPER FISHERIES Several individuals could only be identified to genus level and