What is the “Exploraciones Oceánicas” project?

The “Exploraciones Oceánicas” project consists of a rich phosphate sand deposit identified in Mexico’s exclusive economic zone (EEZ) beyond the country’s territorial waters. The deposit lies within a mining concession licensed to the Mexican company Exploraciones Oceánicas S. de R.L. de C.V. (ExO), a subsidiary of Oceanica Resources. The current resource assessment defines the deposit as containing 588.3 million tonnes of phosphate ore with an average in situ P2O5 of 18.1%, overburden of 1.14 meters and ore thickness of 2.80 meters.

What is the significance of the “Exploraciones Oceánicas” project?

The “Exploraciones Oceánicas” deposit is one of the largest and most important phosphate deposits to be discovered in the world. Dredging of phosphate sands from the “Exploraciones Oceánicas” deposit will offer Mexico an opportunity to correct the trade imbalance that presently exists in its phosphate sector. Currently, the country faces the mounting challenge of affordably obtaining enough phosphate product to manufacture the necessary fertilizer product to feed its citizens. The “Exploraciones Oceánicas” project will produce enough phosphate to meet the country’s growing demands as well as allow it to become a product exporter.

Where is the site located?

The “Exploraciones Oceánicas” deposit is located at a water depth of approximately 70 to 90 meters in the Gulf of Ulloa, in the northeast Pacific Ocean, approximately 25 to 40 kilometers from the coast of Baja California Sur.

Will dredging at the “Exploraciones Oceánicas” site have any adverse impacts on the environment?

A trailer suction hopper dredger will be used to dredge the phosphate sands at the “Exploraciones Oceánicas” deposit site. This type of operation is expected to have a strictly local effect on the seabed biology under the immediate path of the dredge head within an active dredge zone of no more than 1 km2 per year.

Will the “Exploraciones Oceánicas” project affect tourism and whale watching?

No, operations at the site will not be visible from the shoreline. The dredging vessel and associated ore-processing vessel will operate approximately 22.2 km from the coast. There will be no visual effects that might intrude on the amenities of the adjacent coastline, nor will there be shore-based facilities which might affect the Leisure & Tourism industry of the Baja California Sur area.

Will the turtles be threatened or injured by the dredging?

The protection of turtles (particularly the loggerhead turtle Caretta caretta species) is a priority for the design and operation of dredging at the “Exploraciones Oceánicas” site. Loss of turtles is of serious concern in Mexico, and has been mainly attributed to ‘by-catch’ from fishing as well as possibly more complex environmental factors. Regardless of current turtle mortality causes, Exploraciones Oceánicas is committed to active prevention and monitoring of any impacts on turtles that may rarely occur at the dredge site.

For a variety of reasons, turtles are not normally found at depths of 70 to 90 meters. Nevertheless, turtle exclusion devices (‘tickler chains’) and deflection equipment on the draghead, as well as rigorous project management comprises an integral part of the dredging operation.

These measures are proven in shallow waters, where turtle densities are high, to keep losses of turtles by ‘entrainment’ into the draghead to an absolute minimum. By way of comparison, turtle losses by entrainment in shallow water maintenance dredging operations are recorded as less than five turtles per year in the USA, and this is to be compared with estimated losses attributed to fishing by-catch amounting to several thousand per year. The effectiveness of turtle exclusion devices and deflection equipment will be rigorously monitored and any entrainment of individual turtles will be recorded and reported as part of the proposed monitoring procedure specified in the dredging proposal.

Has this dredging technique been used before?

Trailer suction hopper dredging (TSHD) has been carried out for many decades worldwide for aggregate extraction, capital dredging and maintenance dredging. In Mexico alone, more than 220 dredging projects of this kind have taken place. The UK is the second largest aggregate producer after Japan and has invested a more than $50 million between 2002 and 2011 on a major research program to study the impacts of TSHD on the marine environment, and how impacts can be managed and minimized. This program was funded through the UK Government Department of Environment, Food and Rural Affairs. The results and experience from this program have been brought to bear in the design and interpretation of data relevant to the “Exploraciones Oceánicas” dredge site.

The nature and scale of potential impacts of TSHD, and the rates or recovery of biological resources on the seabed are well-understood and fully reported in the international literature. They have also recently been summarized in a book ‘Aggregate Dredging and the Marine Environment: An overview of recent research and current industry practice’ (Newell & Woodcock, 2013). This work shows that the physical ‘footprint’ of aggregate dredging is generally less than 3 km from the point of discharge of excess material from the dredger, and that the biological impact is confined to this zone. It has been shown that recolonization and recovery of biological communities can occur rapidly in fine sands and muds (for review, see Newell et al., 1998; Foden et al., 2009). A recovery time of 2-3 years is not uncommon for sandy deposits, and in some cases significant recolonization can take place within months of dredging cessation.

Will the project affect the local fishing industries?

The dredge site is well outside any of the fishing concession areas that are located along the coastline of Baja California Sur. There are very few seabed resources that comprise a significant food source for benthic marine fauna and the area is of low value for fishing. There will be no impact on local fisheries from the proposed dredging operation at the “Exploraciones Oceánicas” site.