Methods

A FRAMEWORK FOR UNDERSTANDING

The Ocean Health Index evaluates the condition of marine ecosystems according to 10 human goals, which represent the key ecological, social, and economic benefits that a healthy ocean provides. A healthy ocean is one that can sustainably deliver a range of benefits to people now and in the future.

A goal scores highest when the maximum sustainable benefit is achieved through methods that do not compromise the ocean’s ability to deliver that benefit in the future. The Index score is the average of the 10 goal scores.
Calculating Global Goals

All goals are measured in relation to a reference point, or target. Each goal page describes the components used to evaluate it, as well as its reference point, status, trend, pressure and resilience factors. Download the full paper for details on how each goal score is calculated.


10 Human Goals

95
Artisanal Fishing
Opportunities

Local fishing provides jobs and feeds families in communities around the world, especially in developing nations. This goal measures the degree to which a nation permits or encorages artisanal fishing compared to the demand for fishing opportunities, and in the future will include the sustainability of artisanal fishing practices.

85
Biodiversity
Species
.........................
Habitats


An ocean filled with diverse species and flourishing habitats can produce food, jobs, recreation, coastal protection, and other benefits now and in the future. This goal measures the conservation status of marine species and the condition of key habitats that support species richness and diversity.

Biodiversity is divided into two sub-goals: Species and Habitats.

69
Coastal
Protection

Coral reefs, mangroves, seagrasses, salt marshes, and sea ice act as natural buffers against incoming waves, protecting people from storm damage, flooding, and erosion. This goal assesses the amount of protection these coastal habitats provide by measuring the current area they cover relative to the area they covered in the recent past.

74
Carbon
Storage

The ocean and the coastal plant habitats fringing its shores play a major role in slowing global warming by absorbing and storing atmospheric carbon (CO2). This goal measures the current condition or area of coastal plant habitat coverage relative that in ~1980.

78
Clean
Waters

Waters contaminated by pollutants have negatively impact human health, livelihoods, and recreational opportunities, as well as the health of marine wildlife and ecosystems. This goal measures the degree to which waters are polluted by eutrophication (excess nutrients mostly from fertilizers or sewage), chemicals, pathogens, and trash.

33
Food
Provision
Wild Caught Fisheries
.........................
Mariculture


Seafood is a fundamental component of our diet, contributing to the basic protein needs of nearly half of the world’s population. This goal measures the amount of seafood harvested primarily for human consumption and how sustainable it is.

Food Provision is divided into two sub-goals: Wild-caught commercial seafood and Mariculture, or ocean-farmed seafood.

82
Coastal Livelihoods
& Economies
Livelihoods
.........................
Economies


The ocean is an important source of jobs and revenue for individuals, businesses, and communities worldwide. This goal measures a country’s ability to maintain coastal livelihoods and economies in ten marine sectors, from shipping and transportation to wave and tidal energy.

This goal is divided into two sub-goals: Livelihoods, and Economies.

31
Natural
Products

From seashells and sponges to aquarium specimens, non-food ocean resources support local economies and international trade. This goal measures the amount and sustainability of harvest levels pertaining to marine ornamental fish specimens for aquariums, coral products, fish oil, seaweed, sponges, and shells.

60
Sense of
Place
Iconic Species
.........................
Lasting Special Places


People derive a sense of cultural identity from coastal and marine areas. For people living both near to and far from the ocean, knowing that particular species or places exist provides important cultural, spiritual, and personal value. Sense of Place measures the condition of culturally iconic species and the percentage of protected places within a country.

Sense of Place is divided into two sub-goals:
Iconic Species, and Special Places

39
Tourism
& Recreation

Whether it's a day at the beach, snorkeling on reefs, or a weeklong cruise, people enjoy visiting coastal areas and taking part in the many recreational activities that they offer. This goal evaluates the attraction of (priced and un-priced) coastal and marine activities by measuring the number and length of international tourist visits, and sustainability as indicated by tourist density.




Average
65

GLOBAL INDEX SCORE


Calculating the
Ocean Health Index

The Index calculates scores using data for each country’s marine ecosystems within their Exclusive Economic Zones (EEZ). An EEZ is the region extending 200 nautical miles outward from a country’s shoreline.

Each goal is evaluated on the basis of four dimensions. Present Status is a goal’s current value compared to a reference point. Trend is the average percent change of a goal’s value over the last five years. Pressures are the sum of the ecological and social pressures that negatively affect scores for a goal; while Resilience is the sum of the ecological factors and social initiatives (policies, laws, etc) that can positively affect scores for a goal by reducing or eliminating pressures.

The score for each goal is the average of the values for the Present Status and Likely Future Status. Likely Future Status is determined by combining the Trend, Pressures, and Resilience values. Trend is considered twice as important to likely future state as the combined role of Resilience and Pressures, because trends are a more direct measure of the future trajectory of a goal. Efforts that influence a goal’s Resilience require more time to take effect, and changes are often slow to register. The Ocean Health Index does not attempt to indicate conditions further than 5 years into the future.

likely future status is calculated as:

Likely Future Status = Present Status x {1 + (0.67 x Trend) + 0.33 x (Resilience – Pressures)}

using likely future status, each goal score is computed as:

Goal Score = (Present Status + Likely Future Status) divided by 2.

Global Score

The Ocean Health Index combines the 10 goal scores to calculate the overall score for each EEZ. The global score is the area-weighted average of the scores for all EEZs. Individual goals are considered to be equally important, so each represents 10 percent of the global score.

Exclusive Economic Zone (EEZ)

Exclusive Economic Zones (EEZ) represent the areas over which a coastal nation has exclusive regulatory control over economic and resource management. Countries are bordered by Territorial Seas that extend 12 nautical miles offshore; EEZs continue seaward out to 200 nautical miles offshore. Reporting units for the Ocean Health Index include all waters of a country’s Territorial Sea and EEZ; the Ocean Health Index refers to the entire area as the EEZ.

A country can determine the use of marine resources within its EEZs, including fishing regulations, production of wave and wind energy, designation of Marine Protected Areas (MPAs) and the mining of natural resources. Some countries with extensive coastlines, such as the United States, Chile, and Australia, contain multiple EEZs.

EEZs include 40% of the global ocean area and nearly all of the world’s continental shelf area. These areas produce the vast majority of food, natural resources, recreation, livelihoods and other benefits to humans. They are also subject to the majority of impacts from human activities.

Reporting Units

Results reported at the ‘country’ level relate to the EEZ waters of that country. In order to create a common reporting unit, all data were aggregated to the level of country EEZ or region (certain regions combine several EEZs) prior to combining data within goals.


New to the Index for 2013

The 2013 Ocean Health Index reports scores for 221 Exclusive Economic Zones (EEZs), compared to 171 EEZs in 2012. In order to preserve higher resolution information when possible, all 221 areas are reported separately in 2013; whereas the 2012 Index grouped some of the more data-restricted areas together.

New reference points and methods were developed for the Wild Caught Fisheries and Mariculture Sub-goals of the Food Provision goal; and for the Tourism & Recreation goal. More recent data were used for the new calculations of many goal scores. Several goal calculations incorporate entirely new data layers.

Method Changes for the Following Goals

Along with the presentation of new scores for 2013, scores for 2012 have been recalculated using updated methodology and sources to ensure accurate comparisons when measuring change between goal scores from each year. Differences between these recalculated 2012 scores and those previously published represent changes due to new methods. In a few cases, the use of new data or methods made it impossible to recalculate 2012 results, so a small portion of the difference between scores for 2013 and 2012 could still be due to methodological changes.

Wild Catch Fisheries

THIS SUB-GOAL ASSESSES THE AMOUNT OF WILD-CAUGHT SEAFOOD THAT CAN BE SUSTAINABLY HARVESTED.

For 2013 this sub-goal estimates the total population biomass (the weight of fish in the ocean) relative to the biomass that can deliver maximum sustainable yield for each landed stock. The average of those values, weighted by their proportional contributions to the total catch, is the stock status. The goal target is for countries to have their biomass of wild stocks within 5% of the amount that can sustainably deliver the maximum sustainable yield. Countries are penalized for both under- or over-harvesting. Penalties for under-harvesting are half as large as for over-harvesting.

The 2013 analysis used five additional years of FAO catch data, 2007-2011. 2006 was the most recent year used for the 2012 analysis. New methods were used to allocate stocks into EEZs, update values for total biomass for each taxonomic group in each major fishing area, and penalize countries for poor taxonomic reporting. The Taxonomic Reporting Coefficient, (Tc ) employed in 2012 is no longer used. 1,874 stocks had sufficient data for inclusion in the 2013 analysis.

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Mariculture

THIS SUB-GOAL REFERS TO THE COMMERCIAL HARVEST OF SEAFOOD THAT IS FARM-RAISED IN THE OCEAN AND ALONG THE COAST.

As of 2013, the Mariculture sub-goal uses the reference point of harvested tonnes per inhabitant within the 50 km coastal strip. Values for all countries are compared to the best-performing country. The new reference point assumes that production is driven by socially-related factors such as labor force, coastal access, infrastructures and economic demand; and does not assume that all coastal areas have equal potential for mariculture production. The new reference point assumes that two regions with an equal number of coastal inhabitants harvesting an equal tonnage of cultured seafood should score the same.

The 2012 reference point assumed that all coastal ecosystems and countries have similar potential for productivity per unit of area and that all could be developed for mariculture at the same production density as in the most productive country. This unduly penalized countries with long coastlines but low population density, such as Canada.

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Tourism & Recreation

THIS GOAL MEASURES THE NUMBER OF TOURISTS, THEIR LENGTH OF STAY, AND THE SUSTAINABILITY OF TOURISM IN COASTAL AREAS.

The 2013 Index uses the amount of employment in the tourism sector as a proxy for the number of people actually engaged in coastal tourism, assuming that the number of hotel employees, travel agents and workers in related professions increases or decreases relative to the number of tourists.

Status for this goal is calculated as the amount of direct employment in coastal and marine tourism (ET) multiplied by the proportion of the total population within 25 km of the coast and by a sustainability coefficient. ET is estimated for each country as the unemployment-adjusted proportion of the total labor force employed in the tourism sector. Tourists are assumed to distribute themselves along the coast in proportion to the distribution of coastal population.

The 2013 method improves on that used in 2012, because employment in tourism is related to the total number of tourists, both international and domestic. The 2012 method only measured the number of international tourists arriving at airports, then distributed them along the coast in proportion to coastal population distribution (as is also done in 2013), but had no way to account for domestic tourism.

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Natural Products – Fish Oil

Harvesting Non-food Ocean Resources Sustainably

The Status of fish oil production was calculated as the current harvest level relative to its reference point, multiplied by the sustainability of the harvest.

For 2013, sustainability was calculated as the ratio of how close the population’s biomass is to the amount that can sustainably support maximum sustainable yield. This is a change from 2012, when sustainability was calculated primarily by the weighted proportion of species harvested sustainably, i.e. the number of species in each exploitation category (developing, fully exploited, overexploited, collapsed or rebuilding) as defined by FAO and Sea Around Us (Kleisner and Pauly 2011), and weighted by category.

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