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Ocean & Coastal Management journal homepage: www.elsevier.com/locate/ocecoaman
Economic value of marine ecosystem services in Zanzibar:
Implications for marine conservation and sustainable development
Glenn-Marie Lange a, *, Narriman Jiddawi b a b
Policy and Economics, Environment Department, The World Bank, 1818 H St, NW, Washington, DC, USA
Institute of Marine Sciences, University of Dar Es Salaam, P.O. Box 668, Zanzibar, Tanzania
a r t i c l e i n f o
a b s t r a c t
Available online 8 August 2009
Marine ecosystem services are seriously undervalued, resulting in under-investment in conservation and lost opportunities for economic growth and poverty reduction. Economic valuation provides a powerful tool for sustainable development by showing how dependent the economy is on an ecosystem and what would be lost if the ecosystem is not protected. This paper estimates the value of marine ecosystem services in Zanzibar, links the values to the national income accounts, and quantiﬁes how the beneﬁts from each ecosystem service are distributed among ﬁve different stakeholder groups. Marine ecosystem services contribute 30% of GDP, yet the ecosystem is seriously degraded due to both human and natural causes. The paper explores the reasons for this, focusing on the distribution of beneﬁts and the
(dis)incentives this creates for conservation, especially among local communities that steward the marine ecosystem.
Ó 2009 Elsevier Ltd. All rights reserved.
The critical role played by coastal and marine ecosystem services, especially in poor communities in developing countries, is now widely recognized; yet the Millennium Ecosystem Assessment
 reports that these ecosystems continue to deteriorate worldwide, and with them the capacity to support human well-being.
Unless the economic value of all ecosystem services is recognized, their contribution to sustainable economic welfare will be seriously underestimated, resulting in under-investment in conservation and lower incomes.
When integrated with the national income accounts, economic valuation can help two distinct but equally important groups: (1) line ministries, private sector and civil society organizations directly involved in the use and management of the marine ecosystem; and (2) agencies responsible for macroeconomic management, like the Ministry of Finance which controls the national budget and makes policies that indirectly affect the marine ecosystem. The former are often quite receptive to economic valuation, which can clearly help them with management. The latter have no direct responsibility for the marine ecosystem. To engage these decision-makers, we must demonstrate that they also
* Corresponding author. Tel.: þ1 202 473 2735.
E-mail addresses: firstname.lastname@example.org, email@example.com (G.-M.
Lange), Jiddawi@ims.udsm.ac.tz (N. Jiddawi).
0964-5691/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.ocecoaman.2009.08.005 have a stake in sustainable ecosystem management. We do this by integrating ecosystem values with national income accounts in order to show the ecosystem’s inﬂuence on the major indicators of macroeconomic performance, such as the contribution to GDP, employment and the balance of payments, and what can potentially be lost under mismanagement. But it is not sufﬁcient just to estimate values; the distribution of beneﬁts is crucial both for sector-level managers and macroeconomists.
Distribution of beneﬁts is a critical factor for both target audiences but for slightly different reasons. At the sectoral level, information about distribution of beneﬁts contributes to improved management; countless studies have shown that incentives for sustainable management are strongest when beneﬁts accrue to those who steward natural resources. But in many developing countries, local communities often lose out to