Benthic community productivity in the Magellan region and in the Weddell Sea

Our comparison of macrobenthic biomass, production and productivity of the Magellan region (14 - 349 m water depth) and the Weddell Sea (132 - 548 m water depth) is based on multi box corer samples collected in both areas. Biomass is slightly but not significantly lower in the Magellan region (7.3 g C m-2) than in the Weddell Sea (12.0 g C m-2). Annual production and P/B ratio are higher in the Magellan region (5.1 g C m-2 y-1, 0.7 y-1) as compared to the Weddell Sea (3.6 g C m-2 y-1, 0.3 y-1). In the Magellan region, Mollusca, Polychaeta and Arthropoda dominate benthic production, whereas in the Weddell Sea Polychaeta, Porifera and Echinodermata are the most productive taxa

Philadelphia's Councilmanic Prerogative: How It Works and Why It Matters

This report examines the Philadelphia legislative practice known as "councilmanic prerogative," through which individual City Council members make nearly all of the land use decisions in their jurisdictions. This report on councilmanic prerogative is grounded in extensive analysis of city records and interviews with dozens of government officials, developers, political figures, academics, and community advocates. It is the first independent examination of the practice in the city

Physiological capacity of Cancer setosus larvae — Adaptation to El Niño Southern Oscillation conditions

Temperature changes during ENSO challenge the fauna of the Pacific South American coast. In many ectotherm benthic species pelagic larvae are the most important dispersal stage, which may, however, be particularly vulnerable to such environmental stress. Thermal limitation in aquatic ecotherms is hypothesized to be reflected first in the aerobic scope of an animal. Here we present results on whole animal oxygen consumption and on the activities of two metabolic key enzymes, citrate synthase (CS) and pyruvate kinase (PK)) of Cancer setosus zoeal larvae, acclimated to different temperatures. Larvae acclimated to cooler temperatures (12 and 16 °C) were able to compensate for the temperature effect as reflected in elevated mass specific respiration rates (MSR) and enzyme activities. In contrast, warm acclimated larvae (20 and 22 °C) seem to have reached their upper thermal limits, which is reflected in MSR decoupling from temperature and low Q10 values (Zoea I: 1.4; Zoea III: 1.02). Thermal deactivation of CS in vitro occurred close to habitat temperature (between 20 and 24 °C), indicating instability of the enzyme close to in vivo thermal limits. The capacity of anaerobic metabolism, reflected by PK, was not influenced by temperature, but increased with instar, reflecting behavioral changes in larval life style. Functioning of the metabolic key enzyme CS was identified to be one possible key for larval limitation in temperature tolerance

Scientific background document in support of the development of a CCAMLR MPA in the Weddell Sea (Antarctica) – Version 2017 – Reflection of the recommendations by WG-EMM-16 and SC-CAMLRXXXV

The CAMLR Scientific Committee in 2016 reviewed three scientific background documents in support of the development of a CCAMLR MPA in the Weddell Sea. Germany was asked to carry out further work, in particular regarding the issues and questions raised at WG-EMM-16 and SC-CAMLR-XXXV. Here, the authors intend to update the CCAMLR Working Groups on the current state of the work carried out during the 2016/2017 intersessional period. Chapter 1 of this working group paper informs on the new data retrieval process. Chapter 2 presents the updated analyses of relevant data layers, including an update on the Antarctic toothfish habitat model. Chapter 3 provides a sensitivity analysis of the level of protection for Antarctic toothfish and other demersal fish that explores a range of protection-level scenarios. In this context, we show how the cost layer works. Subsequently, a revised Marxan approach based on the updated data layer is shown. In Chapter 4 we outline the way we transferred the results of the scientific analyses into the WSMPA borders and management zones

Doris Abele (1957–2021)

Doris left us prematurely on November 21st, 2021, passing away peacefully, finally losing her long battle against cancer. With Doris, we lost a compassionate human, an excellent scientist, an inspiring leader, and a commendable colleague. We consider it an honour and a privilege to have worked with her for such a long time. We’ll miss but we will never forget Doris Abele

Changes in Arctic Benthos

The shift towards a seasonally ice-free Arctic Ocean raises many questions related to the future of productivity and function of Arctic ecosystems. The highly productive marginal ice zone is dragged closer towards the center of the Arctic, and the ongoing thinning of sea ice and increased light penetration to the surface ocean may change spatio-temporal patterns of under- ice productivity. As under-ice processes are hard to monitor we study the dynamics on (and in) the Arctic seafloor, particularly the macrobenthos, as a proxy for pelagic change. We use biological trait analysis (BTA) to study the benthic functions and responses as this method links species, environment and ecosystem processes (Bremner 2005). Although benthos data from the Arctic and especially from the Arctic deep sea are scarce, international cooperation enables us to compile a dataset ranging over the past twenty years up to today. Based on this dataset we show that benthic functional traits like secondary production are correlated to Arctic sea ice and its associated dynamics. We give a regional example where benthic community functions have changed already over the last twenty years and highlight the areas of the Arctic Ocean that are most prone to these effects. Finally we want to stress the importance of international cooperation in the process of integrating existing data and knowledge to build up a spatially explicit Arctic trait database. Such a database would provide the scientific base to classify the Arctic into clearly defined “eco-function” regions. This functional atlas can then be used by the scientific community to correlate observed environmental trends and predict upcoming changes in ecosystem functioning accordingly