STAR98 Final Cruise Report - NOAA Ship DAVID STARR JORDAN

Southwest Fisheries Science Center PO Box 271 La Jolla, CA 92038-0271 March 11, 1999

 

FINAL CRUISE REPORT

VESSEL:	NOAA Ship DAVID STARR JORDAN, Cruise Number DS-98-10; Southwest Fisheries Science Center Marine Mammal Observation Cruise Number 1612
CRUISE DATES:	31 July - 9 December 1998
PROJECT:	Stenella Population Abundance Monitoring (SPAM98) was a marine mammal assessment survey conducted in the eastern tropical Pacific Ocean (ETP). The survey was carried out with three vessels. The activities of the other two vessels, NOAA Ship McARTHUR and UNOLS Ship ENDEAVOR, are covered in separate Reports.
ITINERARY:	The cruise consisted of six legs with four to six day port calls between each leg. Research was conducted in the international waters of the ETP and in the coastal waters of Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Ecuador, and France (Clipperton Island).

31 JUL		Depart San Diego, CA
31 JUL - 14 AUG		Leg I
14 AUG - 18 AUG		Mazatlan, Mexico
18 AUG - 08 SEP		Leg II
08 SEP - 12 SEP		Panama City, Panama
12 SEP - 01 OCT		Leg III
01 OCT - 05 OCT		Manzanillo, Mexico
05 OCT - 24 OCT		Leg IV
24 OCT - 29 OCT		Puntarenas, Costa Rica
29 OCT - 16 NOV		Leg V
16 NOV - 22 NOV		Panama City, Panama
22 NOV - 09 DEC		Leg VI
09 DEC		Arrive San Diego, CA

 

OBJECTIVES:

The project was a multidisciplinary survey with the primary objective being to estimate the abundance of dolphins affected by the ETP purse-seine fishery for yellow-fin tuna, Thunnus albacares. The survey’s design targeted the depleted stocks of spinner dolphins, Stenella longirostris orientalis (the eastern stock), and spotted dolphins, Stenella attenuata (the northeastern offshore stock). Additional data and samples were collected in order to characterize the physical and biological characteristics of the ETP pelagic ecosystem. This year’s 1998 survey was the first of three (1998-2000) that are planned.

STUDY AREA:

The study area extended from the US/Mexico border, south to the territorial waters of Peru, bounded on the east by the continental shores of the Americas, and to the west to Hawaii (Fig. 1). Past studies indicate this region encompasses the entire distribution of the dolphin stocks most affected by the fishery. The study area was divided into four sampling strata which received varying levels of survey effort: the core area, the outer area, and north and south coastal areas (Fig.1).

PROCEDURES:

Dolphins were surveyed using standard line transect methods. Observers maintained a visual watch for marine mammals during daylight hours (approximately 0600 to 1800) using two 25 X 150 power "bigeye" binoculars mounted on the port and starboard sides of the ship’s flying bridge. Two additional 25 X 150 binoculars were mounted on the flying bridge: one pair for periodic use during sightings and the other pair for bird observations. Total binocular height above the water was 10.74 meters, giving a maximum ship-to-horizon sighting distance of approximately 11.7 km (6.3 nm).

The marine mammal survey was conducted by six observers rotating through three watch positions: port binoculars, data recorder, and starboard binoculars. Observers shifted positions every 40 minutes. At least one identification specialist with previous experience in the ETP was on watch at all times.

The observer at the port binoculars surveyed the area between 10° right and 90° left of the trackline. The observer at the starboard binoculars surveyed the area between 10° left and 90° right of the trackline. Thus, the area 10° to either side of the trackline was covered by both bigeye observers while more lateral regions were covered by one observer or the other. Using unaided eye and 7X binoculars, the data recorder searched the entire 180° forward of the ship, with effort focused on the trackline and the area from the ship out to 300 meters (the "blind" area in the 25X).

The data recorder entered sighting, weather and effort information into a laptop computer on the flying bridge using the software program "WinCruz", developed at Southwest Fisheries Science Center (SWFSC). The computer was linked to the ship’s global positioning system (GPS) to record time and position.

For each marine mammal sighting, bearing (using an azimuth ring on the binocular mount to measure angle) and distance (using a reticle scale inscribed in the eyepiece) were recorded, along with the initial sighting cue. Schools were approached if they were within three nautical miles of the trackline. Observers identified cetaceans, to the level of species/stock when possible, and then made independent estimates of school size. If more than one taxon was present, percent composition for each was estimated independently by each observer.

Seabird observations were conducted concurrently with mammal observations using standard strip transect methods. A single bird observer recorded identity and behavior for all seabirds within 300 m of one side of the ship. Mammal observers on the bigeyes detected feeding flocks within 3.7 km (2 nm) on either side of the ship, and the bird observer recorded size and species composition using the third pair of bigeye binoculars.

When sighted, identification and position of sea turtles were recorded. Turtles close to the ship’s trackline were captured using nets or a small boat. Turtles were measured, weighed, and flipper-tagged and blood samples for genetic and hormonal studies were collected. All turtles were subsequently released.

Helicopter operations were conducted from the DAVID STARR JORDAN in order to obtain photographs of dolphin schools for calibrating observer estimates of abundance, for analysis of cetacean lengths, and for studies of pinniped and seabird colonies. Flights were made in the morning and afternoon during optimal weather conditions: clear skies and sea state below Beaufort 4. All mammal observers on the vessel made estimates of school size and taxonomic composition for schools photographed for calibration.

Cetacean tissue samples for genetic analysis were obtained on an opportunistic basis using hollow-tipped darts fired from a crossbow. Samples were collected from the bow of the ship or from a small boat.

Photographs of cetaceans were taken from the ship and from a small boat in order to verify stock identity and to document geographic variation. Individually identifiable whales were photographed for population studies.

Dipnet sampling for flying fish and other surface organisms was conducted for one hour at night (approximately hours 2000-2100 local time) concurrently with the evening CTD station. Small fish were captured and kept alive for aquarium research and display.

Micronekton biomass between 0 and 500 m was sampled using active acoustics with a Simrad EQ50 echo sounder and two hull-mounted transducers. The echo sounder was operated continuously at 38 and 200 kHz, and interfaced to a data acquisition system. The EQ50 was operated continuously, except when the ship was in the area east of 115 W and between 5 to 20 N, when the transducer was turned off on alternating days in order to test whether the transmission affected dolphin behavior and sighting rates.

Oceanographic data were collected throughout the survey. Two conductivity-temperature-depth (CTD) stations were scheduled every 24 hours: an hour before sunrise and an hour after sunset. A SeaBird CTD with General Oceanics rosette was used for these stations. From each cast, chlorophyll samples (to 150 meters) and salinity samples (0, 500, and 1000 meters or bottom) were collected and processed on board. Nutrient samples (0 - 500 meters) were collected, frozen, and stored for later analysis. Primary productivity was measured by ¹⁴C-uptake. Three expendable bathythermographs (XBT) were dropped daily while underway at 0900, 1200, and 1500 hours local time. Water samples for chlorophyll analysis and bucket temperatures were also collected daily, at 0900, 1200, 1500, and 1800 hours.

A surface manta-tow was conducted for fifteen minutes following the post-sunset CTD station. During Leg IV, a bongo net was towed for 45 minutes to 200 meters following the completion of the manta tow.

RESULTS:

Observers visually surveyed 11,874 kilometers of trackline during the SPAM 1998 survey (Fig. 2). A total of 1,129 sightings of marine mammals were recorded, 960 of which were on-effort. The following tables display preliminary data.

TABLE 1: TABLE 2: TABLE 3 and 4: TABLE 5: TABLE 6: TABLE 7: TABLE 8: TABLE 9:

Marine Mammals Seabirds Sea Turtles Dipnet Samples Biopsy Samples Photogrammetry Effort 35 mm Hand-held Photographic Effort Oceanography

 

SCIENTIFIC PERSONNEL:

Chief Scientist: Dr. Tim Gerrodette, NOAA, SWFSC

LEGS I & II:

1.	Tim Gerrodette	Cruise Leader (Leg I), SWFSC
2.	Robert Pitman	Cruise Leader (Leg II), SWFSC Seabird Observer (Leg I)
3.	James Cotton	ID Specialist, SWFSC
4.	Brian Smith	ID Specialist, SWFSC
5.	Kristin Rasmussen	Marine Mammal Observer, SWFSC
6.	Todd Pusser	Marine Mammal Observer, SWFSC
7.	Elizabeth Moses	Marine Mammal Observer, SWFSC
8.	Ernesto Vazquez	Marine Mammal Observer, SWFSC
9.	Valerie Philbrick	Oceanographer, SWFSC
10.	Kerry Kopitsky	Oceanographer, SWFSC
11.	Brett Jarrett	Seabird Observer, SWFSC
12.	Fritz Hertel	Seabird Observer (Leg II), University of California, Los Angeles (UCLA)
13.	LT Debra Barr	Helicopter Pilot, NOAA
14.	Ron Hegelsen	Helicopter Mechanic (Leg I), Aircraft Operations Center (AOC)
15.	Pete Yates	Helicopter Mechanic (Leg II), AOC
16.	Morgan Lynn	Photogrammetrist, SWFSC
18.	LTjg Alexandra VonSaunder	Photogrammetrist (Leg I), SWFSC
19.	Daniel Palacios	Photogrammetrist (Leg II), Oregon State University (OSU)

LEGS III and IV:

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

Lisa Ballance Paula Olson Douglas Kinzey Lisa Baraff Greg Krutzikowsky Laura Morse Jorge Del Angel Valerie Philbrick Kerry Kopitsky Robert Pitman Fritz Hertel LT Steve Pape Pete Yates Jimmy De La Cruz Jim Gilpatrick LT Tom Martin Morgan Lynn Daniel Palacios Luana Galver

Cruise Leader/Seabird Observer, SWFSC ID Specialist, SWFSC ID Specialist, SWFSC Marine Mammal Observer, SWFSC Marine Mammal Observer, SWFSC Marine Mammal Observer, SWFSC Marine Mammal Observer, SWFSC Oceanographer, SWFSC Oceanographer, SWFSC Seabird Observer, SWFSC Seabird Observer (Leg III), UCLA Helicopter Pilot, NOAA Helicopter Mechanic (Leg III), AOC Helicopter Mechanic (Leg IV), AOC Photogrammetrist (Leg III), SWFSC Photogrammetrist (Leg III), SWFSC Photogrammetrist (Leg IV), SWFSC Photogrammetrist (Leg IV), OSU Scientific Observer (Leg III), SWFSC

Leg V and VI:

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

Lisa Ballance Richard Rowlett Tom Jefferson Stephanie Norm John Mason Cheryl Ryder Juan Carlos Salinas Kathy Hough Valerie Philbrick Kerry Kopitsky Robert Pitman Stuart Pimm LT Debra Barr Pete Yates Ron Helgeson Daniel Palacios Morgan Lynn Jim Gilpatrick Wayne Perryman

Cruise Leader/Seabird Observer, SWFSC ID Specialist, SWFSC ID Specialist, SWFSC Marine Mammal Observer, SWFSC Marine Mammal Observer, SWFSC Marine Mammal Observer, SWFSC Marine Mammal Observer, SWFSC Scientific Observer, (Leg V), SWFSC Marine Mammal Observer, (Leg VI) SWFSC Oceanographer (Leg VI), SWFSC Oceanographer, SWFSC Seabird Observer, SWFSC Seabird Observer (Leg VI), University of Tennessee Helicopter Pilot, NOAA Helicopter Mechanic (Leg V), AOC Helicopter Mechanic (Leg VI), AOC Photogrammetrist (Leg V), OSU Photogrammetrist (Leg V), SWFSC Photogrammetrist (Leg VI), SWFSC Photogrammetrist (Leg VI), SWFSC

 

Prepared by :

__________________________________ Date: _______________ Mr. Douglas Kinzey, SWFSC Biologist   ___________________________________ Date: ________________ Ms. Paula Olson, SWFSC Biologist   __________________________________ Date: _______________ Dr. Tim Gerrodette, SWFSC Chief Scientist   __________________________________ Date: _______________ Dr. Robert Brownell, SWFSC Chief, Marine Mammal Division

Approved by:

__________________________________ Date: _______________ Dr. Michael F. Tillman Science and Research Director, SWR

 

Figure 1 – Area surveyed and four sampling strata of the SPAM98 study.

 

Figure 2 – David Starr Jordan tracklines during the SPAM98 survey.

Table 1 – Number of marine mammal schools sighted during the 1998 SPAM survey from NOAA Ship David Starr Jordan.

Sighting Category	Leg 1	Leg 2	Leg 3	Leg 4	Leg 5	Leg 6	Total
Tursiops truncatus	64	85	7	6	17	29	208
unid. dolphin	32	59	29	23	13	19	175
Stenella attenuata (offshore)	14	26	26	20	5	18	109
Delphinus delphis	9	19	10	10	19	18	85
Stenella longirostris orientalis	5	17	20	8	1	4	55
Stenella coeruleoalba	4	4	10	16	11	10	55
Stenella attenuata graffmani		43	4		4	3	54
Grampus griseus	20	18	5		1	5	49
Zalophus californianus	32				1		33
Steno bredanensis	1	15	3	5		8	32
Balaenoptera edeni	11	7		6	6	2	32
Delphinus capensis	29					1	30
Ziphius cavirostris	12	8	1	1	6		28
Stenella attenuata (unid. subsp.)		20	5			1	26
Physeter macrocephalus	10			7	4	1	22
Kogia simus	13	3	3	1	2		22
Globicephala macrorhynchus	5	3	1	2	5	2	18
Balaenoptera sp.	5				9	2	16
Mesoplodon sp.	10	1	1		2	1	15
ziphiid whale	3	3	2	4	1	1	14
Balaenoptera musculus					9	5	14
unid. large whale	2	4	2	4	2		14
Stenella longirostris (unid. subsp.)		7	3		3		13
unid. cetacean	2	2	3	2	1	1	11
Lagenorhynchus obliquidens	10						10
Delphinus sp.	3	2		1	3		9
unid. fur seal	9						9
Stenella longirostris hybrid		2		6			8
Globicephala sp.	1		1	3	2	1	8
Balaenoptera borealis/edeni			5	2	1		8
Megaptera novaeangliae		2	2		2	1	7
unid. pinniped	4				2		6
unid. small whale	1	1	3				5
Mesoplodon peruvianus	2	1				1	4
Feresa attenuata						4	4
unid. whale	2			1	1		4
Berardius bairdii	3						3
Kogia simus/breviceps	2		1				3
Stenella longirostris centroamericana		2			1		3
Callorhinus ursinus	3						3
Mesoplodon densirostris	1			1			2
Mesoplodon sp. A	1		1				2
Unid. otariid						2	2
Pseudorca crassidens		1					1
Orcinus orca			1				1
Kogia breviceps		1					1
Balaenoptera physalus	1						1
unid. sea lion	1						1
Total	327	356	149	129	134	140	1235

Table 2 - Number of seabirds sighted aboard the David Starr Jordan during the 1998 SPAM survey, listed by taxon and leg.

 

Table 3 – Sea turtle sightings aboard the David Starr Jordan during the 1998 SPAM survey.

Sighting Category	Leg 1	Leg 2	Leg 3	Leg 4	Leg 5	Leg 6	Total
Caretta caretta	2						2
Chelonia mydas			1				1
Dermochelys coriacea					1		1
Lepidochelys olivacea	13	122	16	17	11	21	200
unidentified hardshell			10	12	16	33	71
unidentified turtle	31	777	1		5	2	816
Total	46	899	28	29	33	56	1091

Table 4 – The number of sea turtles tagged (Tag), blood sampled (Blo), and skin biopsied (Bio) per leg aboard the David Starr Jordan during the 1998 SPAM survey. All turtles were olive ridleys (Lepidochelys olivacea).

Leg 1			Leg 2		Leg 3		Leg 4		Leg 5			Leg 6
Tag	Blo	Bio	Tag	Blo	Tag	Blo	Tag	Blo	Tag	Blo	Bio	Tag	Blo	Bio
14	13	1	71	69	4	4	4	4	14	12	1	13	18	1

Table 5 – Dipnet stations and total number of fish collected per leg aboard the David Starr Jordan during the 1998 SPAM survey.

	Leg 1	Leg 2	Leg 3	Leg 4	Leg 5	Leg 6	Total
no. stations	12	20	20	20	18	9	99
no. fish	135	458	401	206	252	113	1565

Table 6 – Number of skin biopsy samples obtained aboard the David Starr Jordan during the 1998 SPAM survey.

Species	Leg 1	Leg 2	Leg 3	Leg 4	Leg 5	Leg 6	Total
Balaenoptera edeni		1		1	3		5
Balaenoptera musculus					15	7	22
Delphinus capensis	19					7	26
Delphinus delphis	2		1		4	11	18
Feresa attenuata						5	5
Globicephala macrorhyncus	7	13	2	2	15	11	50
Grampus griseus						3	3
Lagenorhyncus obliquidens	3						3
Megaptera novaeangliae		1				1	2
Orcinus orca			4				4
Physeter macrocephalus	13				16		29
Psuedorca crassidens		5					5
Stenella attenuata						1	1
Stenella attenuata attenuata	23	9	3	4	12	6	57
Stenella attenuata graffmani	2	55			8		65
Stenella coeruleoalba		2			2		4
Stenella longirostris		17	5		3		25
S. longirostris centroamericana		5			11		16
S. longirostris orientalis	8	26		7			41
Steno bredanensis		3					3
Tursiops truncatus	25	31	6	3	10		75
Tursiops truncatus/Steno bredanensis						2	2
Rhincodon typus (whale shark)		1					1
Total	102	169	21	17	99	54	462

Table 7 – Helicopter photogrammetry effort during the 1998 SPAM survey aboard the David Starr Jordan.

	Leg 1	Leg 2	Leg 3	Leg 4	Leg 5	Leg 6	Total
Hours Flown	4.7	11.6	28	33.5	16.2	27.7	121.7
Schools Photographed (includes whales)	1	15	22	30	19	30	117
Calibration Schools		2	10	12	5	8	37
Pinniped Island Rookeries Photographed	3						3

Table 8 – Cetacean schools photographed by hand-held 35 mm camera during the 1998 SPAM survey aboard the David Starr Jordan.

	Leg 1	Leg 2	Leg 3	Leg 4	Leg 5	Leg 6	Total
Globicephala sp	4		1	1	1		7
Berardius bairdii	1						1
Balaenoptera edeni	1			2			3
Physeter macrocephalus	3			1	1		5
Stenella attenuata (subsp. unid.)		2					2
Stenella longirostris (subsp. unid.)		1		1			2
Megaptera novaeangliae		2	2		2	1	7
Stenella attenuata graffmani		10					10
Stenella attenuata (NE offshore)	2	1		1			4
Delphinus dephis			1				1
Stenella longirostris orientalis	1	1	1				3
Orcina orca			2	1			3
Steno bredanensis				1			1
Balaenoptera musculus					3	5	8
Total	12	17	7	8	7	6	57

Table 9 - Summary of oceanographic data collected during the 1998 SPAM survey aboard the David Starr Jordan.

Type of Sample	Leg 1	Leg 2	Leg 3	Leg 4	Leg 5	Leg 6	Total
CTD casts	19	37	35	35	29	19	174
CTD chlorophyll samples	170	356	357	367	293	195	1738
Surface chlorophyll samples	45	84	68	67	60	57	381
Primary productivity samples	63	117	118	118		63	479
Nutrient samples	183	384	403	401	320	213	1904
Salinity samples	44	78	73	68	48	48	359
XBT drops	29	52	56	54	49	44	284
Manta Tows	11	20	19	11	15	6	82
Bongo Tows				11			11