Chapter V.— THE DISTRIBUTION OF THE MARINE ALG/E IN THE DEEPER 

 WATERS OF BUZZARDS BAY AND VINEYARD SOUND. 



By the deeper waters of Buzzards Bay and Vineyard Sound are meant the depths 

 of 2 fathoms or more, thus excluding the coast line between tide marks and the shallows 

 just below. The reader is referred to the "Description of dredging stations occupied 

 during present Survey," section i, page 201, of this report, for detailed information as 

 to th^ position of the stations, dates of the dredgings, depths, etc., which it is unneces- 

 sary to specify in this general account. 



The varied character of the bottom of Buzzards Bay and Vineyard Sound is respon- 

 sible for many peculiarities of the algal vegetation. There are reefs of large bowlders off 

 certain exposed points, but frequently the bottom in such situations is composed chiefly 

 of rounded pebbles of various sizes. Then there are regions of gravel often mixed with 

 shells and shell fragments, and large tracts of sand which are veritable deserts as far as 

 plant life is concerned. Finally, there are some very extensive regions of black mud, 

 especially characteristic of the upper portions of Buzzards Bay; these are likewise very 

 barren of plant life, except where beds of Zostera marina are present in relatively shallow 

 water. These characteristics are fully described in section i, chapter 11, pages 29-33, 

 and are graphically shown on chart 227. 



The lists of species are arranged after the plan in Collins' "Preliminary Lists of 

 N'ew England Plants: V. Marine Algae," Rhodora, volume 11, page 41, 1900. That is, 

 they are grouped alphabetically in the order of the Chlorophyceae, Phaeophycese, and 

 Rhodophycese. By far the greater number of species in the deeper waters belong to the 

 Rhodophycese, the Phseophyceae coming next in number, and the Chlorophycece claim- 

 ing only a small proportion. 



The dredgings of the survey fall into two groups, (i) those in the middle regions of 

 the Bay and Sound, at some stations within one-fourth of a mile from the shore, but 

 generally in water of 5 fathoms or more in depth, and (2) those "inshore," i. e., imme- 

 diately skirting the coast line in water sometimes as shallow as 2 fathoms. The material 

 in this account will for geographical reasons be grouped under the following headings : 



1 . The middle regions of Buzzards Bay. 



2. The middle r^ions of Vineyard Sound. 



3. Certain inshore regions of particular interest. 



4. Some statistics refative to the distribution of algae in Buzzards Bay and Vineyard 



Sound. 



I. THE MIDDLE REGIONS OF BUZZARDS BAY. 



Buzzards Bay, for con\'tnience in this account, has been divided into an upper and 

 lower portion by a line running from the vjntst end of Naushon (Robinsons Hole) to 

 Round Hifl Point. 



The upper portion of Buzzards Bay in the middle regions has a very scanty algal 

 flora. This is easily accounted for by the character of the bottom, which for the most 

 480 



