Norma Patricia Muñoz-Sevilla

Microscale Governance and Temporal Regulations in Beach Management

This chapter discusses processes and structures of nearshore (marine) and costal governance by focusing on microscale (beach level) situations, inside the Mexican legal and regulatory context. The document compares the efficiency and effectivity of national initiatives, programs and actions with the local –and sometime temporal- measures emanated at beach, community or county level. The principal focus of this research is the lack of articulation and the existence of temporal gaps between managerial decisions related with governance, among national and local institutions and stakeholders, and its impacts towards beach sustainability. Looking at several study places (most of them urban touristic beaches) in the Pacific, Gulf of California and Gulf of Mexico littoral, the paper identify the best local governance (microscale governance) practices, and stablish routes of action toward their implementation at national level.

SEASONAL LEVELS OF HEAVY METALS IN SOFT TISSUE AND MUSCLE OF THE PEN SHELL Atrina maura (SOWERBY, 1835) (BIVALVIA: PINNIDAE) FROM A FARM IN THE SOUTHEASTERN COAST OF THE GULF OF CALIFORNIA, MEXICO

The pen shell ( Atrina maura ) is a filter-feeder bivalve that may accumulate metals in its body. The objective of this study was to determine seasonal concentrations of copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), lead (Pb), arsenic (As), zinc (Zn), and mercury (Hg) in soft tissue and muscle of A. maura cultivated in a farm located in the southeastern coast of the Gulf of California from summer 2011 to summer 2012. Except for Cu, the higher metal concentrations were found during the dry season (winter 2011-spring 2012). The mean values in soft tissue fluctuated from 0.064 ± 0.01 µg/g (dry weight [dw]) for Hg to 485.66 ± 71.12 µg/g (dw) for Zn, while for muscle they varied from 0.058 ± 0.03 µg/g (dw) for Hg to 64.83 ± 4.90 µg/g (dw) for Zn. Concentrations of cadmium (18.15 µg/g in soft tissue and 1.82 µg/g in muscle, wet weight [ww]) and lead (2.31 µg/g in soft tissue, ww) exceeded the permissible limits (36.3, 3.64, and 2.31 times, respectively) recommended by the sanitary regulations of the official mexican standards. The results suggest that variation of metal levels in cultivated pen shell could be influenced by seasonality and anthropogenic activities such as agriculture and aquaculture developed around the culture zone. Continual monitoring of metals in farmed pen shell is recommended.

From Sediment Movement to Morphodynamic Changes, Useful Information from the Modeling World to the Beach Management Practice

Beaches respond in several time and space scales to physical phenomena like wind, waves, tides, storm-surges, littoral currents, river discharges and sea level rise. As a dynamical system they can also be changed due to the influence of biological, geological and chemical processes as well as human-related activities such as urban expansion and port development; construction of coastal protection infrastructure; resources extraction or production and, tourism related actions, among others. In order to properly manage the beaches, any proposed plan or program should preserve the natural structure and function of the beach. In this sense, coastal managers need to choose among several scenarios and managerial options based on the best scientific information available, and one of the most adequate method to do that -considering the cost/benefit-, is looking at the results of coastal simulation models. This paper is focused on coastal processes and review some empirical and numerical models emanated from the coastal engineering arena that can be useful in the practice of coastal management; identify the stages of management in which should be used; and proposes strategies for the proper implementation, monitoring and review of the modeling results, in the context of local beach management.

Primer registro de Perkinsus sp. (Protozoa, Apicomplexa) en el callo de hacha Atrina maura en Sinaloa, México

We evaluated the presence of the protozoan Perkinsus sp. by determining of its prevalence and level of infection in Atrina maura during 2012. Pen shells were collected per season beside an oyster farm located at Estero La Piedra, Sinaloa, Mexico, and analyzed by Rays fluid thioglycollate medium and polymerase chain reaction. The higher prevalence (90%) and infection level (2.3) were obtained when temperature and salinity were higher. The Mackin scale showed a non-infected to moderate infection range. PCR was positive to Perkinsus sp. This is the first record of the presence of Perkinsus sp. in A. maura in Sinaloa, Mexico.