32 DEPARTMEST OF THE .YAF.IL SERVICE 



highest tides, but even.' those much lower down would be exposed foi- a loiig- time at 

 such low tide .js that on January 3. These suffered from the abnormally low tem- 

 perature and without doubt many of them died. But as human beinigs do not eat 

 barnacles, what difference does it make if they were killed off? Human beings may 

 not eat them in quantity, but other animals do. Many fish eat mature barnacles, 

 the various species of viviparous perch and rock cod live on them continually when 

 they are available in localities siiitably situated. In other seasons perch and rock 

 cod could be seen around the piles and near the sheer rocks at almost all times of the 

 year, but this year scarcely one was visible until well on towards spring. They had to 

 go to deeper water to find other supplies of food and these ae well as those previously 

 referred to, may not have had enough food' for the normal growth during that period, 

 or if they had they may have deprived some of the regular inhabitants of the deeper 

 water of their share. 



'Starfish live esteiisively on barnacles and no one who has not seen starfish in 

 certain areas along this coast can realize how abundant they are. This year they had 

 fewer barnacles to supply them with food and hence they attacked clams, cockles and 

 other shellfish to a greater extent. Thus while the shellfish may have been d«ep 

 eniough in the sand or mud to be protected from the frost, they suffered indirectly as 

 the numerous dead shells on various beaches testify. The starfish was not alone in 

 this work of distruclion, the boring mollusc, Thais, probably accounted for a greater 

 number of shell fish than usual, for it too depends on the barnacle to some extent 

 for its food supply* 



Some of the small fish, commonly called "bullheads," althouigh that name is 

 applied to a host of species, feed on barnacles as do a number of the crabs. These 

 in turni serve as food for larger fish such as the svarious flounders', the ling cod 

 (Ophik)don) and the tomcod (H exagrammus) . All of these therefore, had to seek their 

 food supply in deeper water, with less success in all probability. Certainly they were 

 •riot to be found in their usual haunts. 



But this is not all. When the adult barnacles were chilled to death, the eggs 

 from these would also die and quite probably in many cases where the adult was able 

 to survive, the embryos would fail to do so. When the embryos are hatched out they 

 are little shield-shaped creatures with three legs straggling out at each side. Later 

 they grow a bivalve shell and become somewhat changed im shape. In these two larval 

 stages, the nauplius and the cypris, the barnacle is free swimming and it forms an 

 importatit part of the food supply of freely moving forms, different to those that eat 

 the adult barnacle. 



These barnacle lar\'a:' ordinarily are found in plenty during the latter part of 

 January- and from that on until April or even May. This year they were very scarce 

 during the first part of this period. Although the plankton was examined often, it 

 wae not u-ntil April 6 that they appeared in large numbers. It would seem thei*efore, 

 that those far advanced in development, during the cold weather, suffered much more 

 than those in the earlier stages. 



The herring devour these larvai in great numbers, for which purpose they move 

 alonjg in schools parallel to the shore in close proximity to the barnacle zone. Here 

 then is another reason for their late appearance in shallow water last season. Even 

 when they did come in they had to feed on copepods for a time or on their own spawn 

 when it was deposited, but the later larvie kept them -supplied when they appeared 

 so that they stayed in the shallow water later than usual. The young herring 

 immediately after the yolk is absorbed begin to feed on these larvae, but as i* is only 

 the later lot that they make use of, they were probably put to no inconvenience. 



The sand launces feed on the barnacle larvse as the herring do, but they are by 

 no means so plentiful as the herring around Nanaimo. The salmon fry feed on these 

 larvse extensively, probably because they are plentiful, as they will eat almost any- 

 thing that can be swallowed, but, as is mentioned later, the salmo-a fry appeared in 

 the sea much later than usual this year and they did not suffer from any lack. 



