Problem SE8

The sea otter (Enhydra lutris, Fig. 6) was on the verge of extinction in California, because of overharvesting, but fortunately in 1911 an international treaty was signed in order to protect the species. Its numbers have been exponentially increasing, as shown in the table below

Year 1938 1947 1950 1955 1957 1959 1963 1966 1969 1972
No. of otters 310 530 660 800 880 1050 1190 1260 1390 1530

The sea otter has not only increased its abundance but has also expanded its range along the Californian coastline with a speed of about 2.2 km year$^{-1}$. From this information estimate the diffusion coefficient D of the otter, assuming that the habitat (coastline) is one-dimensional.

Figure 6: The sea otter.
\includegraphics[width=0.5\linewidth]{SeaOtter.eps}

Suppose then that you want to introduce a new population of E. lutris into the country of Whatsoever, where only a piece of shoreline, 80 km long, is the right habitat for hosting E. lutris. Outside that piece of shoreline the sea otter cannot survive at all. Assuming that the new population shares the same demographic and dispersal parameters with the Californian population, assess whether the new population can be successful or not.