Marine Atlas: Maximizing Benefits for Vanuatu

TRAVELLERS OR HOMEBODIES: MARINE SPECIES RICHNESS Vanuatu’s marine environment hosts two types of animals: pelagic species and benthic species, both of which are important and biologically interconnected.

Pelagic species are those that live in the water column away from the sea floor and coast. Of- ten these species migrate across vast areas of ocean, driven by oceanic conditions and seasonal food availability (see also chapter “Go with the flow”). On the other hand, benthic species are those that live on or close to the sea floor. Unlike pelagic species, which migrate large distances, benthic species are often associated with specific sea-floor features and are either attached to the substrate or very site-specific. Both pelagic and benthic species contribute to Vanuatu’s rich marine biodiversity, are part of complex food chains, and form important habitats. Furthermore, many commercially important spe- cies of both types are found in Vanuatu’s waters. Commercially important pelagic species include several species of tuna, such as albacore ( Thun- nus alalunga ), bigeye ( Thunnus obesus ), skipjack

( Katsuwonus pelamis ) and yellowfin ( Thunnus albacares ) tuna (FAO, 2010), and several important commercial billfish species, such as blue marlin ( Makaira nigricans ), black marlin ( Makaira indica ), striped marlin ( Kajikia audax ) and swordfish ( Xiphi- as gladius ) (Williams, 2002). There are also some pelagic shark species, in- cluding the blue shark ( Prionace glauca ), oceanic whitetip ( Carcharhinus longimanus ), shortfin mako shark ( Isurus oxyrinchus ), longfin mako ( Isurus paucus ), and silky shark ( Carcharhinus falciformis ). Other sharks such as bull ( Carcharhinus leucas ) or tiger ( Galeocerdo cuvier ) sharks attract countless dive tourists and revenue to Vanuatu (see also chapter “Beyond the beach”). Pelagic species also include the smaller species that support these large commercially important species (see also chapter “Fishing in the dark”). The routes these species take to migrate, and thus the connectivity

Pelagic or benthic?

Some marine species move from one place to another, while others tend to stay in the same location. These species are described as either “pelagic” or “benthic” (see also chapter “Still waters run deep”).

of their habitats, are an important consideration for marine management and conservation planning.

As for Vanuatu’s numerous benthic species, many invertebrates (those without a backbone) are found in soft sediment habitats and on rocky substrates. According to the Ocean Biogeographic Information System, Vanuatu has numerous marine inver- tebrates, including 210 species of hard and soft corals, 939 species of bivalves (such as oysters and mussels) and gastropods (such as snails and slugs), 361 crustaceans (such as crabs, lobsters and shrimps) and many echinoderm species (including starfish, sea urchins, and sea cucumbers). Sea cu- cumbers are particularly important to Vanuatu, with at least 23 species harvested commercially (see chapter “Small fish, big importance”). Many benthic species form habitats in Vanuatu’s shallow waters,

PELAGIC MARINE SPECIES RICHNESS (number of species)

13 - 60 60 - 84 84 - 97 97 - 109 109 - 116 116 - 120 120 - 129

Vanuatu Provisional EEZ Boundary Boundary as deposited at UN Archipelagic Baseline

15°S

100 50

200 km

Copyright © MACBIO Map produced by GRID-Arendal Sources : Becker et al, 2009; Claus et al, 2016; Kaschner et al, 2016; Smith and Sandwell, 1997.

20°S

25°S

165°E

170°E

MAXIMIZING BENEFITS FOR VANUATU

HABITAT VALUES

30