The marine environment of the eastern Mediterranean (Levantine basin) is characterised by an extreme oligotrophy, high salinity (39.5 g/l), high temperature (29 C) and high sediment transport.Marine and Freshwater Biodiversity
The marine biodiversity of the Palestinian Territories is limited to the Gaza Strip. As the name would suggest, the Gaza Strip is a strip of land wedged between the Mediterranean Sea (its western border), the semi-arid Negev desert to the east, Egypt's arid Sinai desert to the south and Israel's semi-humid coastal zone to the north. Gaza's Mediterranean coastline is approximately 40 km long and the strip's width varies from 6 to 13 km. In total the area is 365 km2.
The coastal shelf is 28 km wide in the south of Gaza (ie, to the 100 m depth line) and 14 km in the north. Beyond the 100 m depth line, the sea bottom drops quickly to a depth of 1,500 m. It is part of the Nile littoral system extending from the Nile Delta to the Bay of Haifa. Vast amounts of sediment are transported in an north easterly direction from the Nile Delta towards the Bay of Haifa. The longshore transport is estimated at 350,000 m3 per year. There is a slight imbalance between longshore transport and offshore transport resulting in the continuous, slight retreat of the coastal cliffs of Gaza (Witteveen and Boss, 1996).
The coastline is characterised by coastal cliffs (exposed Kurkar ridges) in the middle to northern section of Gaza and a sand dune system in the south. The coastline is dissected by three rivers: (i) Wadi Gaza in the center; (ii) Wadi Halib in the north; and (iii) Wadi Silka, now completely dry, in the south. The wadi's are seasonal rivers, naturally dry throughout the summer and flowing in the rainy, winter season (Euroconsult et al, 1994).
The marine environment of the eastern Mediterranean (Levantine basin) is characterised by an extreme oligotrophy, high salinity (39.5 g/l), high temperature (29 C) and high sediment transport. Extruding ridges in the sea (exposed Kurkar ridges) form the only hard stable substrate in the shore zone, suitable for colonisation of algae and weeds and are known to be a preferred habitat for several fish species and juvenile fish. The main source of nutrient inflow is the Nile River. The completion of the Aswan Dam in 1967 has denied the eastern Mediterranean an estimated 160,000 million tonnes of sediment per year, further reducing the productivity of the region (Witteveen and Boss, 1996).
In general, the extreme oligotrophy, high salinity and high temperatures limit the flora and fauna in the eastern Mediterranean versus the western Mediterranean. For example dolphins are far more common in the western Mediterranean. And there are limited pelagic species of fish in the region (Witteveen and Boss, 1996).
The building of the Suez Canal in 1869 has led to the influx of an estimated 300 marine fauna species of Indo-Pacific origin. Some examples include the jellyfish Rhopilema nomadica, prawn species Penaeus japonicus and P. monocerus and the swimming crab Charybdis longicollis (Witteveen and Boss, 1996).
Two hundred and forty five bottom dwelling (macrobenthic) species have been identified in the coastal waters of Gaza up to a depth of 80 meters. Higher taxa include: MollIusca (66 species); Crustacea (61); and Polychaeta (50). Of the 245 identified species, 26 are of Indo-Pacific origin. Between the depths of 18 to 20 meters, the sandy bottom is characterised by the decapod crustaceans Sicyonia carinata, Philocheras monocanthus, Diogenes pugilator and Spaeronassa mutabilis. The sandy mud areas lying at approximately 35 to 50 meters are characterised by the Indo-Pacific stomatopod Oratosquilla massavensis and gastropod Cerithium kochi.
Macrobenthic species occuring between 50 and 80 meters depth include echinoderms Brissopsis lyifera and Antedon mediterranea, decapods Parapenaeus longirostris, Macropipus pusillus, Galathea intermedia, Alpheus glaber and ploychaete Sabella pavonia. At the muddy clay bottom of 80 meters, macrobenthic species include mollusca Turritella communis, Nuclea sulcata, polychaete Sternaspis scutata and octoral Alcyonium palmatum. Several decapodes are found at all depths (except along the shoreline). These include; Charybdis longicollis, Myra fugax, Pontocaris cataphracta, and Processa nouveli nouveli (Euroconsult et al, 1994).
The relatively low primary and secondary production levels Levantine basin is reflected in the low fish densities along the coast. Of the reported 540 Mediterranean fish species, 284 representing 108 families are reported in the Levantine basin. Seventy per cent are of Atlanto-Mediterranean origin; 13 per cent cosmopolitan (circumtropical); and 10 per cent of Red Sea origin. Twenty species can be regarded as endemic species. The main pelagic species of commercial importance is the sardine Sardinella aurita (Euroconsult et al, 1994). Table (23) outlines the commercially valuable species caught off the Gaza coast.
Table 23: Commercially Valuable Fish Species.
| Scientific Name | English Name | Scientific Name | English Name |
| Scomber japonicus | Chub mackerel | Pagellus erythrinus | Pandora |
| Diplodus annularis | Annular sea bream | Dasyatis centroura | Roughtailed stingray |
| Trachurus mediterraneus | Mediterranean horse mackerel | Mullus barbatus | Red mullet |
| Solea vulgaris | Common sole | Mobula mobular | Devil ray |
| Sccommerson | Narrow barred Spanish mackerel | Dicentrarchus labrax | Bass |
| Carcharhinidae | Shark | Euthynnus alletteratus | Little tunny |
| Sardinella aurita | Round sardinella | Sepia pharaonis | Cuttlefish |
| Rhinobatos | Guitar fish | Alepes djedaba | Shrimp scad |
| Sphyaena viridensis | Yellowmouth barracuda | Loligo duvaucel | Squid |
| Balistidae | Trigger fish | Hepiramphus far | Half beak |
| Upensus moluccensis | Gold band goat fish | Octapus valgris | Octopus |
| Argyrosomus ragius | Meagre | Caranx crysos | Blue runner |
| Merluccius merluccis | Hake | Postunus pelagicus | Blue swimming crab |
| Siganus rivulatus | Marbled spinefoot | Trachinotus ovatus | Pompano |
| Pomatomus saltarix | Bluefish | Penaeus japonicus | Kuruma shrimp |
| Mugilidae | Grey mullet | Dentex gibbosus | Pink dentex |
| Epinephelus guaza | Dusky grouper | Synodus saurus | Atlantic lizard fish |
| Epinephelus alexandrinus | Golden grouper | Diplodus sargus | White sea bream |
| Hirundichthys rondeletii | Blackwing flying fish | Diplodus cervinus | Zebra sea bream |
Source: CARE/ Ma'an Project, 1996
Prior to 1978, Gaza fishers were allowed to fish both off the coast of Gaza and the Sinai. Following the 1978 Camp David Peace Accord between Israel and Egypt, the area off the Sinai was forbidden and Gaza fishers were restricted to a small trapezoid shaped area off the coast of Gaza between Khan Younis and Gaza City and extending outwards 20 nautical miles. The outward limit was at one point reduced to 12 nautical miles and has recently been extended back to 20. The length (i.e., along the coastline) has recently been extended to roughly the length of Gaza (less a 1.5 nm buffer zone in the north and a 1 nm buffer zone in the south). An ocean area of approximately 1,200 km2 (CARE/ Ma'an, 1996).
Table 24: Gaza Fish Production 1967 to 1996
| Year | Quantity (tonnes) | Year | Quantity (tonnes) |
| 1967-78 (yearly average) | 4,000 | ||
| 1979 | 941 | 1988 | 269 |
| 1980 | 1,300 | 1989 | 388 |
| 1981 | 1,045 | 1990 | 1,837 |
| 1982 | 835 | 1991 | 1,118 |
| 1983 | 1,650 | 1992 | 2,080 |
| 1984 | 605 | 1993 | N/A. |
| 1985 | 274 | 1994 | 1,500 |
| 1986 | 284 | 1995 | N/A. |
| 1987 | 341 | 1996 | 2,500 |
Source: Adapted from CARE/ Ma'an Project, 1996
Table (24) indicates the various stages of the Gaza fishery. The large impact of the closing of the fishing grounds off the Sinai can be seen with the large drop in production after 1978. The next major decline, from 1984 to 1989 is thought to be the result of a further limiting of the area Palestinian fishers were allowed to fish by the Israelis. The next major jump from 1990 to 1993 is most likely the result of an increased level of effort (LOE). This period was the height of the intafada and marked by many long closures of the Israeli/ Gaza border. The result was that Palestinians who worked in Israel were forced to find alternative employment in Gaza and many returned to the fishery. The continuing relative high production from 1994 to present is due to the sustained higher LOE (due both to improved gear and sustained number of fishers).
Photo 11: Fishery Folks in Gaza
Source: PEnA
Marine Mammals and Reptiles
The Gaza Environment Profile (Euroconsult et al, 1994) identifies the sea turtle species Caretta caretta (Loggerhead turtle) and Chelonia mydas as existing in the coastal region of Gaza. The Coastal Zone Plan for Gaza (MOPIC, 1996) identifies two turtle nesting beaches in Gaza. Unfortunately these species and their eggs are under extreme pressure from hunting and collecting and there have been no reported sightings in at least two years. Other marine reptiles reported in Gaza include Eretmochelys imbricata imbricata and Dermochelys coreacea. Little is documented on the status of marine mammals in the Gaza area, other than that the status of the Monk seals, Monachus monachus remains unclear. (Euroconsult et al, 1994)
Marine Flora
Little information on the marine flora of the Gaza area is available. One study, by Dr Madi of the Islamic University in Gaza has begun a small study in this field. The study is ongoing and to date he has identified 10 species of marine algae: Ulva, Enteromorpha, Codium, Ectocarpus, Dictyota, Laminaria, Sargassum, Colpumenia, Bactracospermum, and Cystoseria.
Threats and Impacts
The main threats to marine biodiversity in Gaza is environmental pollution and habitat destruction. It is fair to say that there are no pristine areas left in Gaza, all habitats have been impacted upon. The sand from the dune ecosystems is heavily mined by the construction industry. Wadi Gaza is a stagnant liquid waste dump 9 months of the year, an estimated 42,000 m3 of liquid waste is pumped into the sea daily and the beaches of the north are used as solid waste sites.
The above is the effect of approximately 1,000,000 people living in the 365 km2 area of Gaza. Consequently, the average population density of the Gaza Strip is approximately 2330 persons/km2, while the population densities in the refugee camps range from 29,000 to over 100,000 persons /km2 (Euroconsult et al, 1994).
As mentioned above sea turtles have been hunted into near extinction and their nesting beaches (in the north) suffer greatly from sand mining and pollution.
In such a restricted area, there is great potential for over-fishing. In addition, a large portion of the catch are juveniles, fine mesh nets are used and there is reports of the use of poison fishing techniques. Thus the potential of over-fishing is real and must be monitored.
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