Aerial Images

eelgrass-animation

Above, an animated sequence of Google Earth images from 2005 and 2009, plus a Bing Maps image from 2011, the most recent good quality aerial image of the Studland Bay eelgrass beds available to us. Note the progressive in-filling of gaps in the beds, together with shorewards movement of the inshore edge of the beds. This shows consolidation and expansion of the eelgrass beds over this 6 year period, during which leisure vessels continued to anchor in the Bay. The edge of the beds  moved inshore by 22 metres in that period, across an area where boats are seen at anchor. It is the very opposite of “fragmentation”, the lament of imaginary woe we hear from certain “conservationists”. (Click / tap image to go full screen).

An historic series of aerial images of Studland Bay covering the years 1972, 1985, 1990, 1997, 2008 and 2011 may be found here. They show that, far from declining, the eelgrass beds in the Bay have greatly expanded over that period, and gaps in the beds filled in with new growth, although leisure vessels have been anchoring there throughout the period. We believe this demonstrates sustainability of the eelgrass in the presence of anchoring activity, and a high level of resilience of the eelgrass to anchoring pressures.

A high resolution aerial image of part of Studland Bay in 2008, as used in the MAIA report but with a 50m square grid superimposed for measurement purposes, may be found here. (Click or pinch to zoom in).

More aerial images of the underwater growth in Studland Bay can be found on the internet:

Bing Maps give an excellent and detailed view of the whole bay. Clicking the link (left) will bring up a road map, but by clicking the drop down menu to the right of the “Birds Eye” box above the map and clicking on “Aerial”, the aerial view will appear.  The small image on this page (right) gives an idea of where the main anchoring area (yellow) and the Voluntary No Anchor Zone (red) are located – thanks to Nick Warner of SBPA for this information.

While much of the green stuff in the aerial views is eelgrass, it is not neccessarily so. However, it is clear that where there is no green stuff, there is no eelgrass.

Features worth pointing out are the large bare patch north-east of Redend Point (the point to the left of the yellow oval) – this is an area where boats normally do not anchor, because of shallow water and rocks, so this bare area is nothing to do with anchoring. A little way above (to the NNE of this patch) are other bare areas, again where boats do not anchor, but the shape of these areas strongly suggest that some feature in the seabed, possibly flows of land run-off water, is the reason for these. These features are much better seen on the Bing Maps page.

Not shown on our small image, but well shown on the Bing Map, is the far north end of the Bay, where it comes to a point against the Training Wall. Nobody ever anchors here, but the patchy growth which is often characteristic of eelgrass beds is clear to see.  Again, nothing to do with anchoring.

By default, Google Earth shows the most recent image. To see earlier images, click the History button, the little clock in the top toolbar, and use the slider to move back in time. Note that the date displayed may change, but the image does not always change – the same image may appear under several dates (it’s easy to tell with Studland images, as the pattern of boats is unique to each image capture).

Shown here are low resolution samples of the Google Earth imaging for 2009 (top) and 2005 (bottom). Note that in 2009 there is increased growth both in the anchoring areas ESE from Redend Point and also in the little-anchored areas northward of Redend Point. Also, towards the top of the picture, a new bare area (of seabed, that is) has appeared NE from the car park. This again would seem to be a seabed effect, possibly arising from land run-off water.

These changes in growth patterns occur in both anchoring and non-anchoring areas, and are far greater than any changes that could arise from boats anchoring.