Abstract According to Zertuche-González et al. (2009), Ulva spp. blooms, favored by oyster cultivation, are likely displacing subtidal meadows of Zostera marina in San Quintin Bay, Baja California. The authors propose a partial removal of the seaweed to reduce the risk of eutrophication
and eelgrass displacement in the bay. We warn about the removal of Ulva spp. biomass by raising six arguments that emphasize the necessity of a historical and ecosystem-based management for San
Quintin Bay. First, processes other than competitive exclusion by Ulva spp. blooms more likely explain changes of Z. marina subtidal meadows in the past decade. Second, there is no consistent evidence that oyster cultivation is promoting blooms
of Ulva spp. and the loss of eelgrass. Third, the removal of Ulva spp. biomass is based on experiences of heavily anthropogenically eutrophic systems, while San Quintin Bay is not. Fourth,
the proposed course of actions to restore eelgrass meadows ignores general historical baselines of estuarine and coastal systems
by confusing what it means to be “pristine.” Fifth, despite the important experimental evidence indicating strong top–down
control in temperate seagrass meadows, Zertuche-González et al. (2009) underestimated the capacity of consumers in structuring dynamics of vegetated soft-bottom communities in San Quintin Bay.
Sixth, Ulva expansa may exert positive effects on seagrass ecosystem properties and functions. Instead, we propose protection against the propagation
of unsustainable practices in the bay, and the reintroduction of large consumers that are now absent in this ecosystem. An
ecosystem-based analysis of the role of Ulva spp. on eelgrass dynamics is needed.
and eelgrass displacement in the bay. We warn about the removal of Ulva spp. biomass by raising six arguments that emphasize the necessity of a historical and ecosystem-based management for San
Quintin Bay. First, processes other than competitive exclusion by Ulva spp. blooms more likely explain changes of Z. marina subtidal meadows in the past decade. Second, there is no consistent evidence that oyster cultivation is promoting blooms
of Ulva spp. and the loss of eelgrass. Third, the removal of Ulva spp. biomass is based on experiences of heavily anthropogenically eutrophic systems, while San Quintin Bay is not. Fourth,
the proposed course of actions to restore eelgrass meadows ignores general historical baselines of estuarine and coastal systems
by confusing what it means to be “pristine.” Fifth, despite the important experimental evidence indicating strong top–down
control in temperate seagrass meadows, Zertuche-González et al. (2009) underestimated the capacity of consumers in structuring dynamics of vegetated soft-bottom communities in San Quintin Bay.
Sixth, Ulva expansa may exert positive effects on seagrass ecosystem properties and functions. Instead, we propose protection against the propagation
of unsustainable practices in the bay, and the reintroduction of large consumers that are now absent in this ecosystem. An
ecosystem-based analysis of the role of Ulva spp. on eelgrass dynamics is needed.
- Content Type Journal Article
- DOI 10.1007/s10811-009-9491-0
- Authors
- Pablo Jorgensen, El Colegio de la Frontera Sur (ECOSUR) Km 5.5 Ave. del Centenario Chetumal Quintana Roo C.P. 77014 Mexico
- Silvia E. Ibarra-Obando, CICESE Carretera Ensenada-Tijuana no. 3918, Zona Playitas Ensenada Baja California C.P. 22860 Mexico
- José D. Carriquiry, Universidad Autónoma de Baja Calfornia Instituto de Investigaciones Oceanológicas Apdo. Postal # 453 Ensenada Baja California C.P. 22860 Mexico
- Journal Journal of Applied Phycology
- Online ISSN 1573-5176
- Print ISSN 0921-8971
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