January 2012

26 January. Cruise SW845 was carried out in coordination with the PCCS aerial survey team. Sighting conditions throughout the day were excellent with calm seas, moderate to low temperatures, and unlimited visibility. During the cruise 1 regular and 8 special stations were sampled using nets and vertical pump/CTD equipment in order to assess the available plankton biomass in the water column and to define the distribution and quality of the zooplankton resource influencing the unusually early residency of right whales in the bay. Thirty-one samples of zooplankton, with associated metadata and two oceanographic (CTD/par/fluorometer) observations were recorded. An approximate total of 14 sightings of right whales of at least 10 individuals along with observations of common dolphins, minke, and fin whales were recorded in the eastern quadrants of the bay during the cruise. The right whales observed included two surface active groups during the morning and 6-8 individuals subsurface and skim feeding during the afternoon (the earliest observed skim feeding in the last 25 years).

The zooplankton resource in the eastern portion of the bay is dominated by small copepods with the initial assessment indicating a mixed resource including two taxa of calanoids known to release feeding behavior (Pseudocalanus spp. (now dominant) and Centropages spp.). While the taxonomic composition of the zooplankton resource is not unusual for January, the zooplankton density in the areas of surface foraging is substantially higher than usual, with zooplankton particle densities greater than recorded in any January in the past two decades. Zooplankton samples collected at regular stations at the surface and from the mid water over the past 2 weeks were elevated by as much as an order of magnitude above the “typical” January resource. Though richer than expected in January, the zooplankton collected during SW845 was estimated to be of marginal quality as it has been dominated by taxa calorically less valuable than those dominating the resource during the usual period of right whale residency – late winter and early spring. Thus, while the particle density in the feeding path of right whales was high enough to release feeding, the value of the resource is believed to be marginal. Nevertheless, right whales were documented skim feeding in the afternoon in a pattern more reminiscent of late day feeding during April.

The vertical distribution of the zooplankton, while awaiting analysis, appeared to be concentrated in the upper 10 meters of the water column and to be undergoing late afternoon near-surface concentration, perhaps because of diel vertical migration. In most years of the present conditions, the marginal quality of the resource and unusual amount of social activity, would suggest that right whales are undergoing a brief period of aggregation and confronting a declining quality of the food resource. Therefore, for an aggregation of surface and subsurface feeding right whales to continue into the next week, an increased early (and usually rare) influx of the dominant early march calanoid, Pseudocalanus spp., would have to occur.

Nevertheless, with the already rare oceanographic conditions and the likelihood that water temperatures will remain high, we suggest that these special conditions favor maintenance of the marginal zooplankton resource that has been influencing right whale residency and feeding in the eastern bay for at least the last month and that aggregation and near-surface foraging will continue for the next week, principally along the western margin of the eastern half of the bay, in a band along PCCS vessel track 6.

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

26 January. Our fourth flight of the season came quickly as there are a large number of right whales in the area for this time of the year. We took off from Chatham airport in the early morning and began our survey by flying line 16 north along the eastern shore of Cape Cod. A pair of whales was sighted a few miles east of Truro headed towards the Cape, they were going on long dives with short surface intervals. The northern part of the bay was fairly quiet with just two fin whale sightings and a pod of about 200 dolphins, but once we got down over the waters of the southeast bay there were plenty of right whales to been seen. At least 27 whales were sighted with the majority of them either subsurface feeding or SAGing. Having so many whales in the bay this time of the year is uncommon and it is also unusual for them to be feeding near the surface right now. R/V Shearwater was also out on the water conducting a habitat survey and got excellent additional documentation of this event and will be able to give some insight into the resource currently available for the whales to feed on.

16 January. With blustery winds and even a bit of snow over the weekend the idea getting a flight in anytime soon looked at bit dismal. But then mother-nature shined on us with sunny skies, calm winds, and mild seas – so in the morning we took to the sky form the Chatham airport on our second survey of this season.

We flew coastally along the backside of the cape until we picked up our northern line and began surveying north to south. We were rewarded on our first line with a fin and minke whale. The next line brought our first right whales of the day; this group of six was involved in a SAG near Herring Cove. As we passed Provincetown harbor several dolphins were observed along with many more throughout the northern cape, these groups could possibly be associated with the recent slew of strandings. We documented some of them in hopes of identifying possible stranded ones that were tagged and released the day before.

As we continued along another group of right whales was spotted being social in the south central cape and a few more were subsurface feeding to the northwest of Brewster. We were able to survey the entire bay except for the southernmost line which was partially exposed due to the tide level. With another successful survey we observed 14 right whales, 5 fin whales, 2 minke whales, and several hundred dolphins.

11 January. This was a special habitat assessment cruise generated from right whale observations made by the PCCS Right Whale Aerial Survey team on January 7, 2012 in Cape Cod Bay.

The cruise began in clear conditions with, 2-3 foot seas and 5-10 knot winds. The goal was to assess zooplankton conditions around right whales and at regular stations in the eastern half of the bay. During the cruise up to 3 right whales were seen fluking in the eastern to mid portion of the bay.

The zooplankton resource, dominated by Centropages spp., with presence of Pseudocalanus spp, Tortanus sp., and Acartia sp., appeared to be organized in sub-surface patches. Calanus finmarchicus and Pseudocalanus spp., over much of the eastern portion of Cape Cod Bay was below feeding threshold within the surface and upper water column, hence the absence of the right whales feeding at the surface in this area. The behavior of the whales suggested feeding in the lower water column, below our net sample capacity. Vertical samples were not taken so we are unable to assess the zooplankton resource in the lower water column. Future cruises will be directed toward assessing the zooplankton resource in the water column to better understand the vertical migration of the food resource.

7 January. We have been hearing about right whales in the near shore waters of Massachusetts for some time now, and have been anxious for the weather to allow us to do our first survey of the season. Saturday was our lucky day, with reasonable winds for a January day and hazy weather conditions.

We took off from Provincetown Airport and picked up our first trackline just north east of Cape Cod. We conducted most of our survey with very little excitement. The lack of sightings early on in the survey was a bit of a relief, giving us a little bit of time to get back into the swing of things. As we got further south in the bay we had our first right whale sightings of the season! Our first sighting was a group of right whales in a Surface Active Group (SAG). After getting sufficient photographs to document what individuals were present we continued on our tracklines. Shortly after resuming track we broke again for another right whale sighting. This sighting turned out to be another SAG of approximately five animals.

It did not take us long to realize that one of these animals was entangled. We quickly notified the PCCS disentanglement team, and continued to stand by the animal until the MAER team was able to get to us.

Unfortunately, not long after the disentanglement team arrived we were forced to land due to decreasing daylight. We were able to get good photographic documentation of the entangled animal. Hopefully, this whale sticks around so we can have another chance to work with it when daylight is not an issue.

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