Marine Atlas: Maximizing Benefits for Solomon Islands

TRAVELLERS OR HOMEBODIES: MARINE SPECIES RICHNESS

Solomon Islands’ 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. Often 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 dis- tances, benthic species are often associ- ated with specific sea-floor features and either are attached to the substrate or very site-specific.

Both pelagic and benthic species contribute to Solomon Islands’ rich marine biodiversity, are part of complex food chains, and form important habitats. Furthermore, many com- mercially important species of both types are found in Solomon Islands’ waters. Com- mercially important pelagic species include several species of tuna, such as albacore ( Thunnus alalunga ), bigeye ( Thunnus obe- sus ), skipjack ( Katsuwonus pelamis ) and yel- lowfin ( Thunnus albacares ) tuna and several important commercial billfish species, such as blue marlin ( Makaira nigricans ), black

marlin ( Makaira indica ), striped marlin ( Kajikia audax ) and swordfish ( Xiphias gladius ).

connectivity of their habitats, are an impor- tant consideration for marine management and conservation planning. With the second highest coral diversity in the world and over 500 coral species, Solomon Islands’ waters are home to numerous ben- thic species. Many invertebrates (those with- out a backbone) are found in soft sediment habitats and on rocky substrates. According to the Ocean Biogeographic Information System, Solomon Islands has numerous marine invertebrates, including 885 species

of bivalve (such as oysters and mussels) and gastropods (such as snails and slugs), 285 crustaceans (such as crabs, lobsters and shrimps) and over 200 echinoderm (includ- ing starfish, sea urchins, and sea cucum- bers). Many benthic species form habitats in Solomon Islands’ shallow waters, including corals, seagrass, mangroves and algae (see also chapter “Home, sweet home”). In general, species richness can be used as an indicator of conservation significance. It does not, however, provide information on

There are also some pelagic shark spe- cies, including the blue shark ( Prionace glauca ), oceanic whitetip ( Carcharhinus longimanus ), shortfin mako shark ( Isurus oxyrinchus ), and silky shark ( Carcharhinus falciformis ). 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

PELAGIC MARINE SPECIES RICHNESS (number of species)

13 - 49 49 - 58 58 - 70 70 - 82 82 - 91 91 - 99 99 - 104 104 - 125

5°S

Solomon Islands Provisional EEZ Boundary

50

100

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.

10°S

15°S

160°E

155°E

165°E

170°E

MAXIMIZING BENEFITS FOR SOLOMON ISLANDS

OCEAN VALUES

30