Marine Atlas: Maximizing Benefits for Solomon Islands

THE DOSE MAKES THE POISON: PHOSPHATE AND NITRATE CONCENTRATION While nutrients including phosphate and nitrate provide much-needed nutrients for the marine food chain, too much from agricultural run-off and other sources negatively affect Solomon Islands’ coastal ecosystems.

The mounds of garbage on some coasts pose clearly visible problems. Other types of pollution are less visible—but every bit as serious. TRASH IN THE SURF, POISON IN THE SEA POLLUTION The mounds of garbage on some coasts pose clearly visible problems. Other types of pollution are less visible—but every bit as serious. TRASH IN THE SURF, POISON IN THE SEA POLLUTION

of nitrate in Solomon Islands occur in the east, but the South-West Tropical Pacific (SWTP) is generally considered a nitro- gen-limited area. Phosphate and nitrate concentrations can be higher in the waters close to the main is- lands due to land and coastal inputs, which can include inorganic fertilizers, wastewa- ter treatment from municipal sources, and soaps and detergents. This is where the dose makes the poison: while phosphate

and nitrate are important nutrients, too much of them can be bad for marine and coastal ecosystems. In Solomon Islands’ waters, there is certainly no shortage of sun, and thus photosynthetically available radia- tion, but there is a general limit of phosphate and nitrate. Once these nutrients are add- ed from the land-based activities such as farming and wastewater treatment, primary productivity increases dramatically. The im- pact of too many nutrients (eutrophication) is especially significant in coastal waters,

On a global scale, Solomon Islands’ waters have a moderately low phosphate concen- tration, ranging from 0.16 to 0.27 umol/L. The highest concentrations are observed in the eastern waters and gradually decrease to the west. At the global level, nitrate concentrations in seawater are generally low, with the highest concentrations found in high latitudes and some areas of coastal upwelling. Within Solomon Islands’ waters, the nitrate concentration ranges from 0.3 to 0.7 mmol m3. The highest concentrations

RADIOA CAUSES: power pla countries EFFECTS gan legal ar power that shou already b was final to radioa the ocean clear cata by the gr

NITRATES AND PHOSPHATES CAUSES: Industrial agriculture like intensive animal husbandry and intensive crop cultivation. EFFECTS AND TRENDS: Since the 1950s and 1960s agriculture around the world has developed into a massive industry. Discharge of animal manure and artificial fertilizer reach rivers via groundwater and end up in the ocean, resulting in dead zones off the coasts. International agreements attempt to combat these effects by reducing discharges.

NITRATES AND PHOSPHATES CAUSES: Industrial agriculture like intensive animal husbandry and intensive crop cultivation. EFFECTS AND TRENDS: Since the 1950s and 1960s agriculture around the world has developed into a massive industry. Discharge of animal manure and artificial fertilizer reach rivers via groundwater and end up in the ocean, resulting in dead zones off the coasts. International agreements attempt to combat these effects by reducing discharges.

PHOSPHATE CONCENTRATION (umol/L)

0.38

5°S

0.15

Solomon Islands Provisional EEZ Boundary

50

100

200 km

PLASTIC WASTE CAUSES: Only 20 percent of the plastic waste that ends up in the ocean actually comes from the ocean. The other 80 percent comes from dry land, mainly from countries where there is no, or very poor, waste management. EFFECTS AND TRENDS: Five large garbage patches are known. Most garbage, however, lands on coastlines around the world and is thus a global problem. In 2015, for example, 100 cubic meters of plastic waste collected on the coast of Spitsbergen, a remote island halfway be- tween Norway and the North Pole. The mounds of trash grow larger each year.

Copyright © MACBIO Map produced by GRID-Arendal Sources : Becker et al, 2009; Claus et al, 2016; Smith and Sandwell 1997; Tyberghein et al, 2011.

CHEMICALS AND HEAVY METALS CAUSES: Industrial wastewater and waste gas, mining, burning heating oil. EFFECTS AND TRENDS: According to the OECD, there are around 100,000 different chemical substances in circulation around the world. They include heavy metals like lead and mer- cury but also persistent organic pollutants (POP). Many of these substances are highly problematic because they accumulate in the bodies of marine organisms, entering the food chain where they pose a risk to human health.

PLASTIC WASTE CAUSES: Only 20 percent of the plastic waste that ends up in the ocean actually comes from the ocean. The other 80 percent comes from dry land, mainly from countries where there is no, or very poor, waste management. EFFECTS AND TRENDS: Five large garbage patches are known. Most garbage, however, lands on coastlines around the world and is thus a global problem. In 2015, for example, 100 cubic meters of plastic waste collected on the coast of Spitsbergen, a remote island halfway be- tween Norway and the North Pole. The mounds of trash grow larger each year.

CHEMICALS AND HEAVY METALS CAUSES: Industrial wastewater and waste gas, mining, burning heating oil. EFFECTS AND TRENDS: According to the OECD, there are around 100,000 different chemical substances in circulation around the world. They include heavy metals like lead and mer- cury but also persistent organic pollutants (POP). Many of these substances are highly problematic because they accumulate in the bodies of marine organisms, entering the food chain where they pose a risk to human health.

10°S

where increased nutrients can result in algal blooms (see satellite picture). These blooms can affect coastal habitats such as coral reefs by smothering, in the case of mac- ro-algae, or limiting light availability, which

can lead to rapid declines in reef biodiversity (Fabricius, 2005).

15°S

As the chapters “Plastic oceans” and “From ridge to reef” as well as the graphic show,

160°E

155°E

165°E

170°E

THREATS MAXIMIZING BENEFITS FOR SOLOMON ISLANDS

54