摘要
The River Indus delta is the most prominent feature on the Pakistan coast. Owing to its prominence, mangrove ecosystem, historical, ecological and economic significance it is also a proposed Marine Protected Area (MPA). Currently there are no designated MPAs in Pakistan.This paper presents findings of the Fishery Resource Appraisal Project of Pakistan (FRAPP) a fishery stock assessment carried out for the pelagic and demersal fishery resource of Pakistan from 2009 to 2015 and the Creek Survey Program (CSP) which was part of FRAPP. And discusses how the delta suffers from physical stress.The observations from FRAPP indicates deterioration in the mangrove ecosystem, that are evident in the form of loss of biodiversity and biological productivity. The 600 observations from 10 major creeks showed that trawl catches were a mix of generally small size fish and shrimp. Catches averaged less than 1 kg per tow in all the creeks sampled. Catch weights were somewhat higher in Isaro, WadiKhuddi, Paitiani, Dabbo, Richaal Creeks all of which were near mangrove areas and open sea. The most frequently occurring species of shrimps caught in the trawls belonged to 7 major taxa. The Khobar Creek and Upper Wari Creek are notable for the high rates of occurrence of every group except the Caridea. They are also the only two creeks where the freshwater family Paleomonidae is common. The size composition of the important penaeid family of shrimps in all study areas combined suggests that the smallest shrimps (0.5–1.5 cm carapace length CL) enter the creeks in February/March and adults (5–6 cm CL) move out again 6–12 months later. Four species of Penaeus (monodon, japonicus, semisulcatus, merguiensis), two species of Metapenaeus (monoceros, affinis), Parapeneoposis stylifera and Solenosera sp. were caught, all in low abundance, less than 0.5 Kg tow−1.The shrimp catches in the area off the Sindh coast, the catches averaged 4.30 ± 13.40 kg h−1 on the inner shelf (20–50 m) and 1.7 ± 6.6 kg h−1 on the outer shelf (51–200 m). Further east, on the Kori bank, the shrimp catch averaged 4.40 ± 6.6 kg h−1 (inner shelf) and 1.7 ± 6.6 kg h−1 (outer shelf). Penaeus spp. were more abundant in the inshore and Metapenaeus spp. on the outer shelf.The creeks that have a direct connection to the sea and support a natural mangrove stand are significantly more productive than the smaller creeks. Scientific and management questions have arisen that are addressed in order to help revive the delta and hope that this results in a spillover effect that will spread on to the shelf areas.Fisher communities depend heavily on the delta and coastal waters and its natural resources for their livelihood. Their participation and ownership on the resource is over generations, and therefore their involvement is key to proposing any management and conservation initiatives. The study proposes how the delta and its ecosystem in parts should be protected and why and how it is a prime candidate for being declared nationally as protected. This paper proposes a way forward.