Ensenada de la Paz

Ensenada de la Paz is located on the southeast coast of the Baja California Peninsula. The lands that comprise the WHSRN site are federally owned. For shorebirds migrating throughout the peninsula, Ensenada de La Paz is the last feeding ground of their southbound (fall) migration and the first of their northbound (spring) migration. In general there is little surf, making it possible for fine sediment to accumulate in the southern section of the inlet and form a floodplain where shorebirds feed. The southwest portion of the Ensenada de La Paz, known as Chametla–El Centenario salt marsh, is a floodplain strongly influenced by tides, with more than 1,000 linear meters of wetlands exposed during spring tides. The region’s climate is arid, with an average annual rainfall of 200 mm that is constantly outpaced by evaporation. The tides in this area are mixed semidiurnal. From October to March, the prevailing winds are from the northwest, and from April to September, from the southeast.

Until 2006, the WHSRN site was used by at least 20,000 shorebirds annually. However, in the last few years there has been a notable decline in its use. Surveys carried out during the winter of 2011/2012 recorded 6,800 to 7,500 shorebirds in the zone (Brabata 2012), a reduction of more than 60% in the usual abundance.

The various species and their relative importance remain the same at the site, despite the aforementioned decreases—meaning disturbances have affected the species similarly. The most common shorebirds at the site are: Western Sandpiper (Calidris mauri, 51% of the birds observed in 2006 and 67% in 2011); Marbled Godwit (Limosa fedoa, 7.2% and 6.3%), Semipalmated Plover (Charadrius semipalmatus, 4.2% and 3.6%). Although less abundant, other common species include Black-bellied Plover (Pluvialis squatarola), Willet (Tringa semipalmata), Whimbrel (Numenius phaeopus), Least Sandpiper (Calidris minutilla), y dowitchers (Limnodromus spp.).

Further qualifying the site for its WHSRN designation in 2006 was the fact that the Chametla–El Centenario zone supported more than 1% of the biogeographic population of five shorebird species: Snowy Plover (Charadrius nivosus, 1.13%), Wilson’s Plover (Charadrius wilsonia, 10.61%), Semipalmated Plover (Charadrius semipalmatus, 1.8%), Whimbrel (Numenius phaeopus, 1.01%), and Marbled Godwit (Limosa fedoa, 1.12%). To date, this criterion only applies to Snowy Plover (1.37%, nearly the same as in 2006). Given this, Ensenada de la Paz continues to qualify as a WHSRN Site of Regional Importance, despite the drastic reduction in the number of shorebirds using the site overall.

Ensenada de La Paz is recognized by at least four distinctions: 1) a WHSRN Site of Regional Importance; 2) Priority Wetland for Shorebirds in Mexico (No. 20); 3) a Mexican Important Bird Area (AICA, or IBA, No. 93), category G-1 (global); and 4) a Ramsar Wetland of International Importance (No. 1816).

Fortunately, the tourism mega-project that posed a major threat in 2006 within Ensenada de La Paz, particularly the Chametla–El Centenario beaches, never came to pass. However, other threats persist, such as discharge of solid waste (plastic, rubber, tires, and trash in general), and occasional spills of gasoline and lubricants that have increased as urban growth has increased.  This urban growth is the principal threat at the site, especially construction adjacent to it that uses terrigenous sediment as fill, degrading the area. In some places, new construction practically borders the shorebirds’ foraging areas. Other disturbances associated with human settlements that negatively affect the site include the presence of dogs and cats, foot traffic and vehicles, and constant light and noise. In the image gallery below, there are two aerial photographs of part of the Ensenada de La Paz site, one from 1982 and the other from 2012. Two notable differences stand out: (1) an apparent loss of sublittoral zone and (2) the encroachment of urban development, some of which is located on the mudflats.

As noted in 2006, despite Chametla–El Centenario forming part of IBA 93 (Ensenada de la Paz), with the highest category of G-1, this WHSRN site does not have a management plan. It is of utmost importance to propose targeted measures for conserving this site, such as: regulating construction, controlling the presence of feral fauna (dogs, cats, etc.), preventing the discharge of solid and liquid wastes, and carrying out public awareness campaigns in the community.