Cruise Report W-36 Scientific Activities Woods Hole - San Juan October I2 - November 23, 1977 R/VWestward Sea Education Association .. ", Woods Hole, Hassachusetts DRAFT COpy f \' .. , 1 1 . 1 1 1 1 1 1 1 1 1 1 1 1 1 1 , 1 , 1 1 1 1 1 1 1 1 1 1 1 - <1'I 1 Preface This report is the outcome of a six-week cruise aboard the Research Vessel Westward that took twenty-three students ~cross the western North Atlantic Ocean and the eastern Cgribbe~n Sea. The pages that follow outline the structure of Introduction to Marine Science eNS 225 at Boston Univer­ sity) ~nd ~bstract the research and project work which constitutes its frRmework. Our objective, in addition, is to provide the studints 7ith pn overview of what has been accomplished and the staff ~ith p last opportunity to summarize observations or me~surements whose significance requires reemphasis. The scientific merit and sophistication of the student .. reports ~varies eppreciably; in part this reflects the v!?ri:?ble scientific content of their academic backgrounds. I find it interesting, however, that there are striking '\ exceptions to this correlation. In preparing this report at sea we are imparting to it limit?tions that time, library facilities and reflection could mitigate. On the other hand the students will soon disseminpte ~cross the VIestern Hemisphere and there will be no other opportunity. Arthur G. Gaines, Jr. Chief Scientist November 23, 1977 , , off San Juan, Puerto Rico ii J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J ~ J J J " i J J J J J J J J J J J J J J J J J J J J , J \.. • 1 "'. I J ,.-.1 ·U / J J J ,.,\ oJ'- ''""'" Contents Preface Summary Introduction 1 Itinerary 2 Cruise track 3 Ship's complement 5 Academic Program. 7 Research, Collections and Observations Cooperative Programs 12 Cooperative Ship Weather Observation Program 12 Shark tagging and long lining 12 Plankton Sampling 15 Ichthyoplankton Collections 15 Invertebrate Immunology Study (Schultheiss and Champion) 15 Surface Tension Study (Umhau) 17 Inhouse Programs Surface observations on the ocean and atmosphere Marine ma~ls (Alling) 18 Sea turtles (Colt) 18 Squids (Collins) 22 Birds (Clark) 24 Bird mortality at sea (Clark) 27 Atmospheric transparency (Smythe) 28 Other observations (Huizenga) 29 1. Leg 1: Western North Atlantic Studies Observations on Gulf Stream rings (Rumish) 31 Plankton studies Phytoplankton enrichment studies (Rechen) 34 Floristic demarkation of the Gulf Stream (Farmer and Rechen) 35 Primary productivity of ocean plankton (Ostermann) 35 Sargassum community studies Introduction (Nielsen) 37 Primary productivity of Sargassum (Robinson) 38 Productivity of Sargassum in enriched medium (Lodge) 39 Respiration by macrofauna (Nielsen) 39 The sargasso nudibranch (Travis) 41 A trophic model of the Sargassum community (Gross) 41 Neuston Studies Introduction 42 Distribution of Porpita (Gran~) 42 Standing crop of Sargassum (Robinson) 45 The Search for Echo Bank 46 ( iv 3. Studies at Antigua Plankton observations in English Harbor, Antigua (Farmer, Ostermann,and Wood) 51 Sea level change (Cranston) 56 Caribbean bird observations (Clark) 58 4. Legs 2 & 4: Oceanographic Observations on the Gre·nada Basin Hydrography 61 Mesopelagic fishes (Mitchell) 64 Water transport (Robb) 66 Sediment studies (Wallin) 67 5. Leg 3: Tobago Cays- Studies on a Fringing Reef Complex Reef fauna of the Tobago Cays (Markowitz and Rumish) 71 Biological zonation (Wood) 80 Geology of Petit Tobac (Wallin) 80 Appendices 1- Final examination essay questions. 2- Phytoplankton tows. 3- Bathythermograph casts 4- Neuston tows. 5- Nutrient sampling stations. 6- Plankton observations in English Harbor, Antigua. v Sununary This offering of Introduction to Marine Science was structured about Westward's transect of the Western North Atlantic Ocean and the Grenada Basin of the Caribbean Sea. The course included 30 lec­ tures, 150 contact hours of supervised field and laboratory work, and an individual project for each student. The emphasis of the program reflects opportunities inherent to the ship's track and special skills of the staff, but subject matter treated on W-36 was broad and encom­ passed biologiqal, chemical, physical and geological aspects of ocean­ ography. On leg 1, after very heavy weather which eliminated planned work on Gulf Stream eddies, five students collaborated on studies of the Sargassum community and constructed a trophic model. On this leg primary productivity, nutrient limitation, diversity and abunaance of pnytoplankton were studied. Twelve neuston samples were analysed for their content of tar balls, Sargassum weed, pelagic siphonophores and the marine insect, Halobates. Prior to our first port, Antigua, bathymetric and oceanographic observations were made at the charted position of Echo Bank, an open ocean "shoaltl of questionable exist­ ence that we, also, did not find. On legs 2 and 4 hydrographic stations were occupied in the Grenada Basin. Profiles of salinity, temperature, dissolved oxygen and phosphorus were used to identify water masses and zones of biolog­ ical activity. At these stations students identified mesopelagic fishes from depths ranging to 1000 meters. Drogues were deployed to examine surface current shear; and sediments were taken by gravity corer for analysis ashore. Students prepared species rosters of corals and fishes on leg 3 during three days at the Tobago Cays and immunological studies were conducted on species of sea urchins from the reef. Other projects here dealt with biological zonation and with the geology of a rampart island. Throughout the cruise logs were kept on sightings of marine mammals, birds, squids, turtles ~ on atmospheric transparency and certain meteorological events. The students continued long term SEA projects involving daily transmiss-ioRs of weather observations, long- 1ining'and shark tagging and ichthyop1ankton sampling. Further pro­ gress was made in developing methods to measure surface tension on uncontaminated seawater samples. At port stops special opportunities were taken to study evidence of displacements of sea level and to examine plankton of tropical embaymen t s • The student project reports, abstracted below, were prepared at sea and submitted prior to our arrival in Puerto Rico, the terminal port for W-36. Introduction This offering of Introduction to !-farine Science (L?bor~tory) followed the prescribed curricular criteria according to which lectures, supervised l~boratory and field work ("science ',~;atchrr) and individual project work rec ei ve !3.pproximf. tely equal emph;3. sis. Among these areas individuc-l participp.tion, responsibility and research orient:?tion vary nearly. from one extreme to the other. As is always the case the exact tone of the course is influenced by the special interests of the staff and students. On W-36 these included a relatively broad r~nge of oceanographic topics as is evident from the contents of this report. Where possible we he.ve taken ~dvant8ge of profession~l and academic abilities of the t· ship's nautical staff, which have been unusual both in bre!;;dth!':nd a.ccessibility_ Rese~rch conducted during W-36 partly represents ongoing work of individuals and agencies that have ex­ tended their Rssist~nce to our students. Hateri8.1 re­ Il ported here should not be excerpted or cited without written permission of the Chief Scientist. -1- Table l. Outlined Itinerary H-36 Port Arrival Departure Woods Hole October 12 Antigua October 30 November 3 Be quia November 8 November 9 Tobago Cays November 9 November 12 Bequia November 12 November 14 St. Croix November 21 November 22 San Juan November 23 () -2- o ~oon position (dated) A mid:tight position Hole ~----~~----------~---------+------~4DO u~ITED 5 TATES --+----------+----------+---~~---+-------~5- 10/19 .Bermuda r--r--~----~~------~~--------~--------~H_~~---30· 10/24 --~--------~--------~~--------~~-----~., 10/28 __~4--------___+--------_t;:::~-- 2.0- ico ~~".,. ~ .. f. ... 1 Ant gua • /30 rr., }------+----------+---------+-------~----~~~~---15· (see Fig. 2 ) , ! • Bequia .... T bago Cays I, . SOUTH AMERICA 10- S5- D Fig. 1. ~-1-36 Cruise track (se"e also Fig. 2). -3- / 6S· 11t · ./":' o (/J • • • Q . t\ o " 10/30 () noon position (dated) ~ midnight position 1,'J'~.1.· 11/17 I - '-< \5° P­ 1 I IS' CAP-l BBEi\N SEA " '''' 11/6 ~ 11/7 () 11/1S (.. Bequia ~ '. ~ Tobago Cays ,~ f) ,.:",,1:' A ·,.0 '"'" ·1 r::;? c:::. o I> "' IOD . \/ENflUnA II 60" '"P."KoB~ Fig. 2. W-36 Cruise track in the Caribbean Sea (see also Fig. 1), () . (), " c n Table 2. W-36 ship's complement. N:?uticpl Staff Wpllece C. Stark, J.D.s M.M. Captain Rick Farrell, B.~. Chief Hate C,?rl M. B.sum, B. S. 2nd Mate Rod Oekes 3rd Mate John Thompson, B.E. Chief Engineer S",lly K2ul, B.S. Ste's8ra. Scientific Staff Mary Farmer, Ph.D. Scientist-2 Arthur G. Gaines, Jr., Ph.D. Chief Scientist Paul Markowitz, B.S. Scientist-3 Students College Home Abi gEdl ( Ga y ) Alling Middlebury Mt. Kisco, N.Y. College, Vt. Jean Champion Boston U., Mass. San Francisco, (G)* Calif. Loralee Clark st. Mary's Coel City, Ill. College, }unn. Christine Collins Boston U., Mass. Methuen, Mass. .Edward (Ned) Colt Connecticut Dedham, Hass. College, Conn. Jeremy Cranston Cornell U., N. Y . HiddletovIn, R. I. Kimberly (Kim) Grane College of IdethO, Scottsdale, Idaho J\..riz. Robin Gross Simmons College, Halden, Mass. Mass. Donc.>ld Huizenga Colorado College, Rochester, Minn. Colo. Peter Lodge U. of Rhode Providence, R.I. Island, R.I. John Mitchell Northern Hichigan Spring Lake, U., Mich. Mich. Carolyn Nielsen Dennison U., Cincinnati, Ohio Ohio Dorinda (Rindy) Ostermann Pomona College, South Pasadena, Calif. Calif. Susan Rechen U. of Maryland, Kensington, l'Td. Md. (G) David Robb Boston U., Hass. McLean, Va. Leslie Robinson Oberlin College, Hilton, Mass. Ohio Bruce Rumish Adelphi U., N. Y. Wantagh, N.Y.