Wednesday Aug 22, 2018

Site Visits Phase II

 

Based on the site visits of phase II,The coastlines between Kangan and Assaluyeh are formed of rocky mountains/cliffs fronted by narrow beaches.  The area features many wadis or short flood rivers, which bring sediment from the higher land and leave them as fan deltas on the coast.    Beaches in this area are mostly made of cobbles, pebbles and coarse sand on the bedrock.  Sand normally appears in the upper beach around the high waterline.  The rest of the beach is usually covered by pebbles and cobbles either as a lag or in thick layers.  Cobbles become exposed particularly during low tide.

Naiband and Dayyer on east and west end of the Phase II study area represent sandy beaches with mild slope that have been formed in the valleys of Gavbandi and Dayyer rivers, respectively.  Sediments on the beaches of the study area are mostly carbonate made by molluscs, most of which is very young.  In addition, because of the episodic fluvial transport, there is addition of older carbonate material from the land.  The old carbonate is structureless and grey in colour. Cobbles are mostly limestone derived from terrestrial sources.

There are a number of ports in the Phase II study area: Asaluyeh, Nakhl e Taghi, POGC, Shirinoo, Petrochemistry, Parak, Taheri, Tombak LNG, Iran LNG, Kangan and Dayyer.  Assaluyeh, Shirinoo and Parak Ports have sedimentation problems.  Direction of net alongshore sand transport is generally from the west towards the east.

Coral cover on Naiband reefs is quite high, although the diversity is rather low-the coral community is dominated by Platygyra, Porites and faviids.  There is little Acropora-evidently it all died during a warming episode early in the century.  Fish density and diversity were remarkably high.  Parrotfish 50 cm long were observed in 5 m of water, groupers were abundant.  There are many turtles.  Naiband Bay is a biodiversity hotspot, one which deserves to be protected.

The amount and extent of the coral still living off the ongoing oil and gas development is surprisingly large.  The observed area would probably average between 10 and 15% coral cover.  By comparison, it is generally agreed that the maximum average coral cover on some of the healthiest reefs in the world (for example, the Great Barrier Reef of Australia) is about 45%.  Typical values of coral cover for "healthy" reefs worldwide would average about 30%. 

There is little doubt that the coral cover on these reefs has decreased recently, judging from the widespread evidence of dead coral on the bottom and at some beaches.  Nonetheless, what remains is certainly worth saving. There has not been a great deal of quantitative description of the reef resources of Iran, hence it is not surprising that these reefs have not as yet been described in the international scientific literature.

The fish life we observed could be described as adequate for such a stressed environment.  Several groupers of reasonable size (~30 cm) were observed, and judging from the quantity of abandoned fishing line on the bottom this is a favourite spot for fishing.  Few Parrotfish were observed, which is somewhat worrisome.  Coral reefs are always in a race with algae, and reefs survive best when the algae are kept down by grazing organisms such as Parrotfish and Sea Urchins.  It is most probable that the parrotfish have been fished out.  They are usually caught in wire traps.

نقاط بازدید زمینی، محدوده کنگان و دیر در تصویر ماهواره‌ای IRS 2003
Ground visit points, Dayyer and Kangan areas on IRS 2003 satellite image.

نقاط بازدید زمینی، محدوده تمبک و اختر در تصویر ماهواره‌ IRS2003

Ground visit points, Tombak and Akhtar areas on IRS 2003 satellite image.

 


Last Update : Mar 14, 2012 08:44