Farallon Institute Newsletter - Spring 2023

Around The Office

At the 50th Annual Meeting of the Pacific Seabird Group (PSG), held this last February, the Lifetime Achievement Award was given to Farallon Institute’s Bill Sydeman “For exemplary lifelong contributions to seabird ecology, academic excellence, and fostering collaborative, multidisciplinary science worldwide”. Bill was nominated for this award by his peers and selected by a PSG committee to receive it. We at Farallon Institute exceedingly appreciate Bill for his excellent leadership, and we congratulate him on this much deserved recognition by PSG.

State of the Ocean — Central-Northern California

What a winter season we are having! Coming out of a warm fall due to an offshore marine heatwave that ended in October, we have had a cool winter with normal ocean temperatures. This is more or less what we can expect from the still-present, although weakening, La Niña conditions.

But what nobody could predict was the stormy and wet winter still taking place across California. Normally, La Niña brings dry conditions to central and southern California, while El Niño brings above normal rains. This time, however, rain and snow amounts are above average, very much above the recent years that led us into drought conditions. These are not normal La Niña conditions in California but they are dissipating fast, and El Niño could develop in the next couple of months.

Near the coast, ocean temperature conditions were fairly normal in the late fall and winter. Recently (late February) we experienced our first upwelling events of the year, and they cooled off the water temperatures of central and northern California (Figure).

Humpback whale pregnancy rates

Humpback whale populations around the world are recovering from the intense whaling industry of the 20th century, including in the Southern Ocean around Antarctica. There, however, a relatively new fishery is developing that harvests krill from the ocean. Krill are key prey for humpback and other baleen whales. New collaborative research explored the link between krill abundance in Antarctica and humpback whale pregnancy rates, and how climate change may also be affecting these dynamics.

The study took place in 2013–2020 along the West Antarctic Peninsula and whale pregnancy was determined from hormonal tests of blubber samples. Pregnancy rate in the population each year was related to krill abundance and a local calculated metric of climate change: the day of spring ice edge retreat (sIER), which is the day in which sea ice concentration decreases below a set threshold amount (indicating the “edge”) and remains below this amount for at least five consecutive days. 

Statistical results showed that humpback whale pregnancy rate varied significantly from year to year (from 30% to 86% of females age 1+ in the population), and each year’s rate strongly correlated with krill abundance and date of spring ice edge retreat in the previous year. Pregnancy rates were higher when the sea ice persisted longer into the spring and krill were more abundant in the previous year (see Figure above). It is not entirely surprising that pregnancy rates are related to food abundance at an earlier time – whales do not feed while breeding and raising calves, so they must fatten up before this takes place. Knowing specifics of this relationship between whale reproductive rates and environmental effects provides information that can be used in krill fishery management and the understanding of climate change effects. In this case, a reduction in the amount of sea ice and/or krill could lead to lower humpback whale pregnancy rates that could have negative effects on their populations.

Read the full study here.

Historic UN Treaty for the High Seas

On March 5th, after two weeks and two decades of talks, the United Nations members agreed on a new treaty to establish protections in the high seas of the world – the open ocean area not part of any country’s jurisdiction. This treaty aims to protect the ocean’s biodiversity from climate change, overfishing, seabed mining impacts, and other threats by allowing the creation of marine protected areas and implementation of conservation measures where there is currently no international agreement or organization that can do so.

While this agreement must still be ratified and adopted by the signing countries’ governments, it is part of the ocean goals of the 2030 Agenda for Sustainable Development, and also of a bigger agenda of what is now referred to as the ‘30x30’ initiative to protect 30% of the world's environmental habitat by the year 2030. If this treaty is ratified, it will be the first time most countries unite to regulate the high seas since 1994 (signed in 1982), when the UN Law of the Sea was established. Back then, however, biodiversity was not the primary aim of many countries’ protection measures, and definitely wasn’t considered at a global scale. This treaty is an opportunity to make positive and potentially restorative environmental efforts that will affect the entire planet.