INVESTIGATION OF THE PLANKTON OF THE IRISH SEA, 
TABLE IT. 
| 
149 
(Jen. char. of weather. 
Sunshine early spring. 
Snow in spring; sunshine. 
Sunny spr., dull summer. 
Dry warm spr. & summer, 
Mild spr.,cold wet summer. 
Wetspr., dry,calm summer. 
| Temp. higher, sunshine. 
Wet, stormy spr., cool yr. 
| Cold spr., wet & dull year. 
Cold spr., wet Aug., storms. 
| 
Dull mild spring; wet. 
Cold wet spr.,dry summer. 
Mild wet spr., dull summer. | 
Year. | Diat. max.) Temp. Char. of Plankton. 
1907 ... Mar. 41°  Thalassios. & Microcal. 
08... May 43 Later than ‘07, 
09 ... Apr. 41  , Like ‘OR; more June Pl. | Dry, sunny spring. 
10 .... Apr. 44 | More Diatoms. 
ll... May 42 | Oceanic invasion. 
| much sunshine. 
12 .... A.&Ju. 45 | Earlier than '11, abundant. 
13 ....| May 44 | Oc. invas.— A sterionella. 
14 . May 45 | Chætoceras. 
15 ....| May 43 No swarms. 
16 ....| June 40 — Cheetoceras; Ceratium. 
17 ...., May 40 Diatoms high in spring, 
low in aut. 
18 ....| May 42 Diatoms abundant, & early. 
19 ....| May 42  Calanus searce. | 
20 aa. May 43 More Pl; like ‘18. | 
21 ....| May 45 Diatoms abundant, & early. 
JAN. FEB. MAR. APR. MAY. 
payussypy 8224634 
, BASKSGSSSTRGEASIS SSSEALASISSSLRaTS 
} 
Dry & warm, sunshine. 
JUNE. JULY. AUC. SEPT OCT. NOV.-DEC. 
2 9 1623306 15 2027)8132027|3 101724| | 8 1522295 1219243 10172431|7 H2128|4- H 1825|2 9 1823308 13 202714 11 1525 
HAE 
4 x) 
THT 1 nus N 
any 1 Ms 
DT ^ / x - ; a. M | te 
"SEA » s ini T | à x 
- ™ A LLL KIT L 
A eL HHHH IL 
TN HEC EE 
] Y | BARRES VER 
DATA TU : HH dl 
WEEKLY AVERACE TEMPERATURE NEN 
/ OF THE AIR AND SEA AT Sau AT aa : 
CT PORT ERIN DURING THE YEAR L1 
TI TI IT TI 7 77 77 r | 4 
TTT TT yt Tt TT yy | 1 
CET | | 
Diagram of Sea and Air temperatures at Port Erin. 
As may be seen, from this diagram of the sea and air temperatures at 
Port Erin during 1909 (and the various annual diagrams do not differ much) 
the sea temperature lags behind that of the air, and is generally as low, if not 
lower, in March, at the time when the phytoplankton is waking up to activity, 
as it is in January or February. 
