Aplicación teórica del árbol de evaluación del Marine Stewardship Council, como herramienta de gestión de pesca sostenible, a la pesquería de la chirla, Chamelea gallina (Linnaeus, 1758), con draga hidráulica en el Golfo de Cádiz

La etiqueta azul del Marine Stewardship Council, pesca sostenible certificada, indica que un producto de pescado, fresco o transformado, procede de un recurso natural, salvaje, gestionado de manera respetuosa con el medio. Para obtenerla es necesario cumplir una serie de requisitos que son evaluados por una empresa certificadora (a la cual MSC ha dado el visto bueno y que es, a su vez, evaluada por otro organismo que asegura su completa imparcialidad). MSC presenta un modo de gestionar pesquerías que, según la propia organización, asegura la continuidad de la especie objetivo, de otras especies dependientes de ésta y del medio donde habitan. Sin embargo, obtener dicha eco-etiqueta azul es complejo y, sobre todo, económicamente difícil. El objetivo de este artículo es comprobar si el enfoque ecosistémico de este estándar ayudaría a paliar el impacto negativo de una pesquería que es fuente de riqueza, alimento y empleo perdurable en el Golfo de Cádiz. Es decir, aplicar los principios y criterios de MSC como herramienta de gestión de la pesquería de la chirla, Chamelea gallina (Linnaeus, 1758), con draga hidráulica.

How can an invasive grass affect fire behavior in a tropical savanna? A community and individual plant level approach

Some invasive grasses have been reported to change fire behavior in invaded plant communities. Urochloa brizantha is an aggressive invasive grass in the Brazilian Cerrado, an ecosystem where fire is a common disturbance. We investigated the effects of U. brizantha on fire behavior in an open Cerrado physiognomy in Central Brazil. Using experimental burnings we compared fire behavior at both the community and the individual plant level in invaded (UJ) and non-invaded (NJ) areas burned in July. We also assessed the effect of fire season in invaded areas by comparing July (UJ) and October (UO) burnings. We evaluated the following variables: fuel load, fuel moisture, combustion efficiency, maximum fire temperature, flame height, and fire intensity. Additionally, we evaluated the temperatures reached under invasive and native grass tussocks in both seasons. Fuel load, combustion efficiency, and fire intensity were higher in NJ than in UJ, whilst flame height showed the opposite trend. Fuel amount and fire intensity were higher in October than in July. At the individual plant level, U. brizantha moisture was higher than that of native species, however, temperatures reaching ≥600 °C at ground level were more frequent under U. brizantha tussocks than under native grasses. At the community level, the invasive grass modified fire behavior towards lower intensity, lower burning efficiency, and higher flame height. These results provide essential information for the planning of prescribed burnings in invaded Cerrado areas.