Dear James, we have several flood plain rivers in Iran that are announced as the protected areas. The reason for such announcement is based on biological activities. Some of these rivers have rare species such as red-patched trout(Oncorhynchus mykiss). The others are protected for strogens and so on. They really do not work well unless the local people are educated about the importance of river ecology.

James, I would think the extensive literature on marine reserves would give some insight, to answer your questions you need to think about site fidelity, mobility and life history. Reserves are particularly useful for defined stages of LH, e.g. juvenile stages that require specific habitat. There does seem to be a relationship between area size and LH in relation to effective protections (see our Blyth-Skyrme et al. paper in Cons Biol.

Hi James, it seems that the effort to protect the river basin is a good start, as compared to no effort being made. Nevertheless, it would also depend on the existing issues and the socio-demographic profiles of those living within the existing river basin, in order to say whether the establishment of protected area work or fit into the specific context, and if there is no other way of 'protecting it'. I am involved now a project on land use conflicts within the river buffer zone in Malaysia, and we are focusing on the governance of the water resources, which is in the initial stage (1st year of the 4-year project). Will update on this platform about the outcome.

About the abundance of fishes and the size of fishes, perhaps the first criteria to decide about getting a flood plain protected, is the evidence of the ecological significance, in this case, could be the distribution of fishes (and the fishes' characteristics). On the spill over effects, fishes are free to swim border-less-ly, If there is spill over effects later, perhaps the idea of bio-sphere reserve could work?

Sounds like an interesting and promising project, James!

Protecting a riparian area or floodplain forest will have reach-out far beyond the borders/limits of the protected area...

What measure you take to control for success probably depends on what the (major) aim of protecting this area? Connectivity seems an important issue to me, and there is some literature on how to estimate this. To this end, fish may be a good indicator because of their motility, but inverts (both aquatic and terrestrial) should also be monitored when testing for success...

You might find good resources via Wetlands International. Also check out RAMSAR.

I believe understanding whether there are bigger fishes in the flood plains and whether there are spill over of fish into adjacent unprotected areas is a question of stock assessment. Tools like otoliths shape and otolith chemistry are possible options to assess growth of fishes and discriminate between stocks.

Good idea James!! Yes, you may use expert knowledge for that. Area is a factor here. I worked for the protected area system, their classification and delineation of potential areas in the regional scale. Mostly terrestrial and only fresh water aquatic ecosystems or protected lands were taken into account. I think this will be a good plot to think. Hope, will get nice outcomes from this. You may look for Borja's works for such ecosystems and protected areas. Best regard.

You might want to examine the literature on the Yolo Bypass in the Sacramento - San Joaquin Delta of California. Experimental work on benefits of this floodplain surrounds primary and secondary production in situ and downstream, fish rearing experiments in cages on rice fields in the floodplain during flood up, and fish abundance and condition of wild populations in adjacent channels, combined with stable isotope work to determine the source of productivity. Good luck!

This is a very interesting question. The basic principles that make a MPA working well is to have a no take zone with no fishing and a buffer zone with regulated fishing. At the sea, this basic regulation permits to recover quickly the abundance, size and genetic diversity inside the reserve and the diffusive process due to differences in density and linked to the home range movement of individuals permits the spill over of biomass from the reserve to the buffer and adjacent areas, improving fisheries.

However these processes are very linkied to life history of species and the pecularities of the marine populations (high fecundity and short age at maturity, etc.). In other environments, this traits are different ant they will condition the functioning of the protected area.

Epicontinental aquatic environments has an aditional difference: direccionality of the process. I am convinced that in lakes the concept of MPA will work well, but in rivers more research would be needed to say this as the directionallity of the fluxes can affect the results.

If you are interested in bibliography on MPA functioning, I could provide some of it.

It's an interesting idea, but I have to agree with Hong Ching Goh about the need to understand what other issues might be affecting the biota of the proposed protected areas. In Australia, our major issues with rivers and floodplains revolve around flow regulation, exotic species, influences from surrounding land uses (including direct land use on the floodplain), and fragmentation of river systems caused by weirs, dams, etc. Next to these, fishing doesn't rate a mention. Currently, we're putting most effort into environmental flows, with major public investment programs like the 'Basin Plan' for the Murray-Darling Basin.

This is an interesting idea, especially in the major tropical rivers where a significant proportion of the species present rely on floodplains either for breeding or as nursery areas. There are, however, certain issues that need to be considered. Firstly the floodplain cannot be set apart from the main river channels as many species have complex life strategies with feeding, breeding, nursery and refuge habitats that are spatially quite separate. Apart from obligate floodplain dwelling species that permanently inhabit floodplain features such as lagoons or wetlands most species only occupy floodplains during the flood season. This means that for a species (or behavioural guild) to persist all habitats need to be conserved as well as the connectivity between them. Secondly, as already mentioned, the health of river fish populations (and the annual harvest from floodplain rivers) is very much conditioned by the magnitude and duration of annual flooding. As flood regimes are increasingly determined by other uses of water and the river basin, such as water abstractions for agriculture and damming for power generation, and floodplains themselves are increasingly being modified for agriculture, many of the processes that regulate river fisheries are basin level phenomena and need to be negotiated at that level. It is, therefore difficult to set aside sectors of the floodplain for conservation without taking all other uses of the basin into account.

definitely ----- this can be a good idea

It's certainly an interesting question with implications well beyond fish. I am in the early phases of protecting a section of floodplain. Phase 1 was to eliminate corn production. We put in a cover crop to reduce soil erosion into the river. At this point we are planting trees on an ongoing basis and permitting self seeding. The next phase will be to reconnect and restore wetlands destroyed by the agriculture. Your question adds an other dimension to my thought process: will we impact the fish? I certainly anticipate new fish in restored wetlands....but the river? Who knows?