The Index calculates scores using data for the 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, or until it meets with the neighboring country. 

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 combined score of current status, trend, pressures and resilience form the score for each OHI goal and sub-goal

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 = Present Status x {1 + (0.67 x Trend) + 0.33 x (Resilience – Pressures)}
Goal Score = (Present Status + Likely Future Status) divided by 2.
Global Score
The Israeli Mediterranean Health Index combines the 9 goal scores to calculate the overall score for the Israeli EEZ. Individual goals are considered to be equally important, so each represents 11.11 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, or until it meets with the neighboring country EEZ, for example, in 2010, an EEZ was set within the territorial waters between Israel and Cyprus at the maritime half way point. Reporting units for the Israeli Mediterranean Health Index include all waters of a country’s Territorial Sea and EEZ; the Israeli Mediterranean 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. 
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, prior to combining data within goals.


Method Changes for the Following Goals
Differences in data availability in Israel compared with the data sets used for the global assessment have raised the need to develop new methods and set new reference points. Targets by public officials were set for several goals.  

Carbon Storage

The decision to exclude carbon storage from Index calculations was based on two main factors. The first is that there are no data available on the only carbon-fixing ecosystem found in the Israeli Mediterranean, the seagrass beds. There have been sightings of some patches of seagrass, but these have never been documented or mapped. This habitat seems to be rare. A second reason for not including carbon storage in the Index is the fact that the Levant basin of the eastern Mediterranean is considered ultra-oligotrophic, characterized by extremely low productivity, enabling non-significant amounts of carbon storage.

Tourism and Recreation

The Israeli Mediterranean assessment Mariculture sub-goal uses the official reference point of 8,000 tons of fish harvested by year 2020. The new reference point assumes that production is driven by socially-related factors such as labor force, coastal access, infrastructures and economic demand.

Artisanal Fishing opportunities
Artisanal fishery is limited by fish resources in Israel. The exploitation status of coastal fish species was calculated using the exploitation categories: Developing, Fully Exploited, Overexploited, Collapsed, and Rebuilding. These categories are modeled on those used by the FAO, and calculated using algorithms developed by the Sea Around Us Project, using the current landings relative to the historical peak catch and the trend for each species.

Tourism and Recreation
The Israeli Mediterranean Index uses the amount of coastal park visits and hotel occupancies as a proxy for the number of people actually engaged in coastal tourism, assuming that the number of tourists in coastal parks is more indicative of a healthy ocean than coastal city hotel occupancies.
Status for this goal is calculated using a weighted average of park visitation numbers and hotel occupancies with half the weight of "parks" given to "hotels". Hotels reference points were taken from official planning targets for 2020. "Hotels" status is the number of occupied beds divided by the official target and multiplied by tourism sustainability index. "Parks" target is the highest number of tourists recorded per park. Since the coastal parks are managed by the Israel Nature and Parks Authority, which is the governmental body charged with the protection of nature, landscape and heritage in Israel, we assume that the tourism in these parks is managed sustainably.

Natural Products 
The collection and trade in natural resources, such as aquarium fishes and corals, is prohibited in Israel. However, Israel relies heavily on sea water to provide drinking water for over half the households, by way of desalination. The desalination of sea water was incorporated into the index as the Natural Products goal.
Studies on the effect of desalination on the environment show a different reaction of each habitat to desalination effluents, much depending on local environmental conditions. Sustainability of desalination is a subject very little studied. We developed an index to assess the sustainability of desalination in Israel, based on reported measurements of its effects on the benthos, monitoring of the salinity and location of the saline plum of effluents in relation to receiving habitats, and their sensitivity.
The status of the Natural Product goal is calculated as the amount of sea water being desalinated versus the official goal of 750 million cubic meters set for 2020, while assessing its sustainability.

Sense of place- Lasting Special Places 

In Israel, building within 100 m of the shoreline has been prohibited by law since 2004. Beaches of special public interest are mostly coastal projects that had been authorized for development before 2004, and they have caused civil protest activities. Thus, a new data layer was added to the archeological sites and proposed marine protected areas, composing the lasting special places: beaches of special public interest.  

The targets of Lasting Special Places sub-goal are: to protect 10% of the coastal  waters, according to the Convention of Bio-Diversity; to protect the declared archeological sites from trawling activities; and to preserve the beaches that are of public interest.

Clean Water
The targets for Clean Water goal have been changed according to available data and official targets: 
Trash – Adapted from the Ministry of the Environment: 70% of the samples clean/very clean, according to the Trash Index. 
Pathogens – Below the Ministry of Health’s threshold value for enterococci: less than 104 per 100 ml.
Chemical pollution – Heavy metal (Pb, Cd, Hg  As) concentrations in coastal fish tissue that are below the Ministry of Health’s guideline on maximal concentration threshold values.
 Nutrient pollution – Nitrate concentration in coastal water that are below 0.6 micromolar.

Biodiversity – Habitats

The Habitats sub-goal measures the conservation status of two habitats – sandy shores and sub-tidal soft-bottom habitats for which information was available. 
The soft-bottom habitat is under environmental stress from various sources, but the most direct ruin is caused by trawler boat gear traction. The condition of the soft-bottom habitat was assessed as 1–  soft-bottom habitat destruction stress factor. 
The condition of the sandy shore was estimated according to its areal extent in recent (2012) mapping, compared with the 1970 areal extent. The trend was calculated by comparing with the 2006 areal extent.
There was no available data regarding the condition of the rocky reefs or tidal flats. Therefore, the coastal protection by Rocky habitats was not included in this assessment.

Coastal Protection 
Tidal flats and rocky reefs provide natural shore breakers. A wide sandy shore is the habit that provides biological coastal protection on the Israeli Mediterranean shore (we do not evaluate protection afforded by human-made or geological features). 
Coastal Protection – Sandy Shore
The condition of the sandy shore was estimated according to its areal extent in recent (2012) mapping, compared with the 1970 areal extent. The trend was calculated by comparing with the 2006 areal extent.
Coastal Protection – Rocky Habitats
There was no available data regarding the condition of the rocky reefs or tidal flats. Therefore, the coastal protection by rocky habitats was not included in this assessment.

Tourism and Recreation

Coastal parks visit numbers and coastal hotel room numbers and occupancy data were used to assess the number of people enjoying the coast. A high score means that park visit numbers are the highest ever recorded, hotel room numbers are reaching the Ministry of Tourism targets, and that there is a high score for tourism competitiveness reported  in Israel.

Sense of Place Lasting Special Places
The reference point for Lasting Special Places is protecting marine and coastal areas designated as MPAs by the Israel Nature and Parks Authority in order to comply with the Convention of Biodiversity’s target to conserve at least 10% of coastal and marine waters by 2020; declared archeological sites; and beaches of special public interest, which represent civilian struggle against shoreline development (see the section on Specific Data Layers for more details).