February 2012

29 February. PCCS right whale habitat program cruise SW850 was conducted in calm conditions (sea state 1), moderate temperatures, and periods of light snow. The cruise was directed at zooplankton collections in an area of the bay not previously sampled, a location very close to the Barnstable shore where the PCCS aerial survey reported a number of socializing and feeding right whales. During the cruise 17-21 right whale sightings were recorded and photographed for individual identification and health assessment. In addition to two vertical casts producing 21 zooplankton samples with mid water oceanographic data, 10 zooplankton samples were collected from the surface and water column at regular stations and one special station. SW850 was shortened due to low visibility in moderate snow.

Throughout the eastern part of the bay at regular stations sampled on SW849 and SW850 conditions remain unfavorable to aggregation and feeding by right whales, with low quality surface and mid water zooplankton samples suggesting poor foraging conditions. The quality of the zooplankton sampled at special stations associated with the aggregation of right whales in the far southwestern quadrant of the bay contrast with the general conditions in the larger Cape Cod Bay system. Discreet water column samples collected using a vertical pump system revealed the presence of a zooplankton layer of moderate to high density at a depth of 7 meters, which was composed of a mixed copepod resource dominated by the calanoid copepods Pseudocalanus ssp., Centropages spp. and Tortanus, taxa that have begun to decline in the greater bay system. The complexity of the present resource condition coupled with the unusually early and wide distribution of the right whales, and the appearance of good foraging conditions along the western shore of the bay, does not conform to observations made in late February or early March of past years.

Zooplankton resources throughout the bay continue to be unfavorable to right whale aggregation except in small areas in the southwest and far northeast quadrants, hence the potential for aggregation and feeding by right whales in the bay will depend upon the durability of the zooplankton resource in the areas where the resource is eliciting feeding, and upon the influx of Calanus, which in previous years has begun to appear in high densities during the latter part of March. The poor quality of the zooplankton resource throughout the bay belies the influence of a significant resource found in these localized areas identified in collections during SW850. Though resource conditions do not favor aggregation and feeding by right whales, it appears that continued residency of the whales will depend on the richness in these areas and should the Calanus resource enter the bay earlier than usual, continued residency and feeding may be expected. Without the entry of Calanus within the next week to 10 days continued residency is unlikely.

Unusually high concentrations of pteropods persist in mid-water samples at most regular stations in the bay.

These observations are considered preliminary pending detailed analysis and final assessment reporting.

27 February. PCCS right whale habitat studies cruise SW849 was conducted in moderate conditions (sea state 1-2) and moderate temperatures. This first cruise after the gale force winds of the weekend was directed at documenting the area where a moderately rich zooplankton resource controlled the right whale aggregation that had been resident in the southern portion of Cape Cod Bay for more than a month. During the cruise 6-7 right whales were sighted in the far northeastern quadrant of the bay. Resource information and oceanographic data were recorded at 6 stations including a special station in the vicinity of socializing whales. SW849 was shortened by a rising strong SSE wind. Conditions in the bay appear to have changed over the last week with a decrease in the higher than average surface water temperatures (as recorded by the vessel’s surface thermistor) likely initiated by deep mixing during the storm event of the last days. Nevertheless, sea surface temperatures remain above the average recorded during the last 13 years. The previously reported uncommonly high concentration of pteropods found at many stations in the southern bay persists, though patchy, in the mid water column, appearing in samples collected in the north central bay with oblique nets sampling to 19 meters deep).

The zooplankton resource in the eastern half of the bay has continued to decline and is now dominated by low to moderate concentrations of smaller zooplankters, principally Pseudocalanus and Centropages and including a complex mix of a many taxa. The early season enrichment of the bay by the calanoid Pseudocalanus, reaching a peak not seen during previous Februarys, appears to be declining. With the decline of the Pseudocalanus peak that usually controls the late winter distribution of right whales and a decline in the general zooplankton productivity at regular stations, conditions in the eastern portions of the bay have become unfavorable to right whale aggregation and feeding; these circumstances suggest a continuing dispersal of right whales and departure from the bay. Given these conditions the risk of entanglement or ship strike will remain very low.

These observations are considered preliminary pending detailed analysis and final assessment reporting.

29 February. PCCS right whale habitat program cruise SW850 was conducted in calm conditions (sea state 1), moderate temperatures, and periods of light snow. The cruise was directed at zooplankton collections in an area of the bay not previously sampled, a location very close to the Barnstable shore where the PCCS aerial survey reported a number of socializing and feeding right whales. During the cruise 17-21 right whale sightings were recorded and photographed for individual identification and health assessment. In addition to two vertical casts producing 21 zooplankton samples with mid water oceanographic data, 10 zooplankton samples were collected from the surface and water column at regular stations and one special station. SW850 was shortened due to low visibility in moderate snow.

Throughout the eastern part of the bay at regular stations sampled on SW849 and SW850 conditions remain unfavorable to aggregation and feeding by right whales, with low quality surface and mid water zooplankton samples suggesting poor foraging conditions. The quality of the zooplankton sampled at special stations associated with the aggregation of right whales in the far southwestern quadrant of the bay contrast with the general conditions in the larger Cape Cod Bay system. Discreet water column samples collected using a vertical pump system revealed the presence of a zooplankton layer of moderate to high density at a depth of 7 meters, which was composed of a mixed copepod resource dominated by the calanoid copepods Pseudocalanus ssp., Centropages spp. and Tortanus, taxa that have begun to decline in the greater bay system. The complexity of the present resource condition coupled with the unusually early and wide distribution of the right whales, and the appearance of good foraging conditions along the western shore of the bay, does not conform to observations made in late February or early March of past years.

Zooplankton resources throughout the bay continue to be unfavorable to right whale aggregation except in small areas in the southwest and far northeast quadrants, hence the potential for aggregation and feeding by right whales in the bay will depend upon the durability of the zooplankton resource in the areas where the resource is eliciting feeding, and upon the influx of Calanus, which in previous years has begun to appear in high densities during the latter part of March. The poor quality of the zooplankton resource throughout the bay belies the influence of a significant resource found in these localized areas identified in collections during SW850. Though resource conditions do not favor aggregation and feeding by right whales, it appears that continued residency of the whales will depend on the richness in these areas and should the Calanus resource enter the bay earlier than usual, continued residency and feeding may be expected. Without the entry of Calanus within the next week to 10 days continued residency is unlikely.

Unusually high concentrations of pteropods persist in mid-water samples at most regular stations in the bay.

These observations are considered preliminary pending detailed analysis and final assessment reporting.

27 February. PCCS right whale habitat studies cruise SW849 was conducted in moderate conditions (sea state 1-2) and moderate temperatures. This first cruise after the gale force winds of the weekend was directed at documenting the area where a moderately rich zooplankton resource controlled the right whale aggregation that had been resident in the southern portion of Cape Cod Bay for more than a month. During the cruise 6-7 right whales were sighted in the far northeastern quadrant of the bay. Resource information and oceanographic data were recorded at 6 stations including a special station in the vicinity of socializing whales. SW849 was shortened by a rising strong SSE wind. Conditions in the bay appear to have changed over the last week with a decrease in the higher than average surface water temperatures (as recorded by the vessel’s surface thermistor) likely initiated by deep mixing during the storm event of the last days. Nevertheless, sea surface temperatures remain above the average recorded during the last 13 years. The previously reported uncommonly high concentration of pteropods found at many stations in the southern bay persists, though patchy, in the mid water column, appearing in samples collected in the north central bay with oblique nets sampling to 19 meters deep).

The zooplankton resource in the eastern half of the bay has continued to decline and is now dominated by low to moderate concentrations of smaller zooplankters, principally Pseudocalanus and Centropages and including a complex mix of a many taxa. The early season enrichment of the bay by the calanoid Pseudocalanus, reaching a peak not seen during previous Februarys, appears to be declining. With the decline of the Pseudocalanus peak that usually controls the late winter distribution of right whales and a decline in the general zooplankton productivity at regular stations, conditions in the eastern portions of the bay have become unfavorable to right whale aggregation and feeding; these circumstances suggest a continuing dispersal of right whales and departure from the bay. Given these conditions the risk of entanglement or ship strike will remain very low.

These observations are considered preliminary pending detailed analysis and final assessment reporting.

27 February. After being on the ground for over a week due to high winds, the PCCS aerial team took off early Monday morning to try and get in a few hours of flying before the winds picked up again in the afternoon. After taking off from Chatham airport we conducted a survey of Cape Cod Bay beginning in the north and heading south. We did not spot any right whales until Race Point where one right whale, one fin whale and approximately thirty dolphins were spotted. A total of twelve right whales, five fin whales and about 30 dolphins were spotted on the entire trip. Most of the right whales that were spotted were in SAGs or traveling, no feeding was observed.

As the day progressed, the weather steadily declined. We completed thirteen out of our sixteen tracklines, and then we were forced to land due to the high sea state and increasing winds.

15 February. Right whale habitat program cruise SW848 was conducted in calm overcast conditions and moderate temperatures. In order to document the zooplankton resource during what appears to be a period of changing right whale behavior and possible departure from Cape Cod Bay, 18 samples were collected in the broad vicinity of 15-20 right whales, most in courtship behavior. Particular focus was placed on sampling in the vicinity of whales that moved to the far northern portion of the bay. Samples were collected using both a vertical pump system and surface nets. Forty-two right whale sightings (several sightings were possible duplicates) were recorded and half were documented for photo identification during the cruise.

The controlling zooplankton resource in the areas sampled inside and outside the bay appears poor and below what is estimated to release feeding behavior. Although no whales were observed feeding during the cruise, samples in the vicinity of social whales were dominated by low concentrations of calanoid copepods, Pseudocalanus ssp. and Centropages typicus and by pteropods. A full water column collection east of the mouth of Cape Cod Bay, near the path of a socializing pair of whales indicated that the low plankton density is found throughout the water column.

The relatively low concentration of zooplankton throughout the area sampled, even in the vicinity of right whale aggregations, coupled with the broad scale movement of numbers of whales north to the far northwest portion of the northeast quadrant, strongly suggests the departure of a significant portion of the whales that have been resident and feeding in the bay for the past 6 weeks. Although areas of somewhat elevated zooplankton density may be found in the bay, the overall decrease in the food resource is unfavorable to the continued residency, aggregation, and feeding by right whales in the bay. Because of the unusual characteristics of the 2012 season (see below) it is difficult to forecast the controlling patterns of resource distribution and enrichment, however it seems likely that a continued decrease in right whale numbers will be observed over the next week and feeding activities will become less likely as time passes.

Conditions in Cape Cod Bay continue to be substantially different than those observed in the last 25 years of research. Preliminary observations from PCCS aircraft and vessel studies suggest an unusual combination of factors with:

– water temperature at 1 meter depth during January and the first ½ of February running approximately 2 degrees C higher than the average of the last 28 years,

– zooplankton density and species dominance in the first weeks of February were similar to conditions at the end of March,

– an unusually high concentration of pteropods sometimes dominated zooplankton samples, releasing right whale feeding behavior, but found in samples from previous two decades as only a minor constituent of the plankton,

– right whales resident in the bay starting in early December in numbers not usually seen until late March,

– surface and subsurface feeding observed intermittently from mid-December through January, conditions not observed at such an early date since1982,

– social (SAG) behavior seen with much greater regularity than in the past.

These unusual conditions suggest that the Cape Cod Bay system is substantially different from those documented in the past. We suspect that the present anticipated exit of whales from the bay will continue and that right whales will aggregate and feed at the surface only in response to the usual third wave of zooplankton, Calanus finmarchicus, which in usual years appears in high concentrations starting in April. With the early decline in Pseudocalanus, the increase in Calanu

These observations are considered preliminary pending detailed analysis and final assessment reporting.

15 February. Today brought us the most right whales seen to date this season but with a slightly new distribution pattern. So far the majority of our whale sightings have been concentrated in the southeastern section of the bay, with most of the behaviors being either SAGing or feeding. Today started strong with several whales traveling south along the Atlantic shore of the cape. As we continued along a group of surface and subsurface feeding whales was encountered east of Pilgrim Lake, and in this area we could see the plankton concentrations in the water. Then between Race Point and Provincetown light was a group of SAGing whales along with many other individuals and small groups in the general vicinity. As we surveyed throughout the bay other smatterings of whales were sighted, a few of these were SAGing or traveling but most with no discernible behaviors and no feeding was observed within the bay today. In total at least forty-five right whales, one minke whale, and one fin whale were sighted during the survey.

5 February. Today the PCCS aerial team surveyed coastally along the eastern shore of the cape and then ran transects north to south through the bay. The flight got off to a slow start with no whales sighted during the first hours. But once we found the whales they were everywhere, the weather improved throughout the day and our sightings also continued to increase. Several groups were sighted and a few individuals, most were SAGing or skim and subsurface feeding. The whales were again concentrated in the southern and central to easterly part of the bay. Most of the whales that were sighted feeding were in the south central section. We resighted a previously known entangled whale which was first seen entangled in the bay early this year. Today it was associated with several other individuals that it has been hanging around with throughout much of this season. The PCCS Marine Animal Entanglement Response Team was able to quickly respond and evaluate the entanglement. At the end of the survey we had sighted at least 35 right whales and one feeding fin whale.

2 February. The PCCS aerial team took off from Chatham airport and conducted a south to north survey of Cape Cod Bay. On the second trackline of the day the plane spotted a SAG of four right whales with a solitary animal close by. The next few tracklines also produced a few animals skim feeding, and then another SAG of six whales. With each sighting the plane circled, photographed and documented the behavior of the whales. As the day progressed, the weather steadily declined. After flying five tracklines, we had to call it quits when the choppy sea state made finding whales very difficult.

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