The Mangrove Line: Q1 2013 and Jamaica’s Shrinking Coastal Forests

Briefing

• National mangrove assessment documented hundreds of hectares lost over two decades.
• Kingston Harbour shoreline mangroves reduced to fragmented remnants from coastal reclamation.
• Negril Morass mangrove boundary retreating under development and drainage pressure.
• Fishers linked declining coastal fish catches to mangrove nursery habitat loss.
• New regulations proposed requiring mangrove impact assessment for coastal development applications.

Jamaica’s mangrove forests had been in long decline before the 2013 assessment named the extent of it. The causes were well understood: land reclamation for coastal development and aquaculture; alteration of the hydrological systems that mangroves depend on through drainage works and coastal infrastructure; direct clearing for building; and the accumulated effects of pollution and changed sediment dynamics from upland land use. What the 2013 assessment added to this established understanding was precision: specific loss estimates for specific coastal areas, a comparison with earlier survey data that established the rate of loss, and a spatial analysis that identified where the remaining mangrove cover was most intact and most at risk.

The findings were not reassuring. Kingston Harbour’s shoreline, which had once been fringed with mangrove forest and was still home to mangrove habitat in the 1960s and 1970s, had by 2013 been reduced to small fragmented patches — remnants that persisted in the interstices of the commercial and industrial development that had replaced the continuous forest. The Negril Morass, the wetland system on the southern end of Seven Mile Beach that had historically been one of Jamaica’s most significant coastal wetland areas, had contracted significantly. Some of the contraction was the result of documented illegal land reclamation. Some was the result of drainage infrastructure associated with agricultural land to the east. And some was the indirect result of coastal development that had changed the water table and salinity conditions in ways that shifted the mangrove boundary.

The Fishers’ Testimony

The testimony of fishing communities about the relationship between mangrove loss and declining catches was consistent across parishes and consistent with the ecological science. Mangroves serve as nursery habitat for a wide range of commercially important fish and invertebrate species: juveniles settle and develop in the complex root structures of mangrove forests before moving to reef and open water habitats as adults. The loss of mangrove nursery habitat does not eliminate those species from the water column immediately; it reduces recruitment, the supply of young fish entering the adult population, over a time lag of years. Fishers who had been observing declining catches over a decade were, in the assessment’s framing, observing the lagged ecological consequences of mangrove losses that had occurred a decade and more earlier.

Regulatory Proposals

The proposed requirement that mangrove impact assessments be incorporated into coastal development applications represented a regulatory response that, if adopted and enforced, would have meaningfully changed the incentive structure facing developers. Under the existing regime, mangroves were protected in principle but the assessment burden on development applications did not explicitly require quantification of mangrove impacts or offsetting. The proposed change would make mangrove impacts visible in the planning process in a way that they had not previously been. Whether the proposal would be adopted, and whether if adopted it would be enforced with the consistency that its conservation intent required, remained to be seen in 2013.

Related: Property Market Analysis | Latest Jamaica News

Follow Jamaica Homes on Youtube @jamaicahomes and Instagram @jamaica_homes and on Facebook @jamaicahomes Send us a message or email us at onlinefeedback@jamaica-homes.com or editor@jamaica-homes.com