Globally, many fish species are overexploited, and many stocks have collapsed. This crisis, along with increasing concerns over flow-on effects on ecosystems, has caused a reevaluation of traditional fisheries management practices, and a new ecosystem-based fisheries management (EBFM) paradigm has emerged. As part of this approach, selective fishing is widely encouraged in the belief that nonselective fishing has many adverse impacts. In particular, incidental bycatch is seen as wasteful and a negative feature of fishing, and methods to reduce bycatch are implemented in many fisheries. However, recent advances in fishery science and ecology suggest that a selective approach may also result in undesirable impacts both to fisheries and marine ecosystems. Selective fishing applies one or more of the "6-S" selections: species, stock, size, sex, season, and space. However, selective fishing alters biodiversity, which in turn changes ecosystem functioning and may affect fisheries production, hindering rather than helping achieve the goals of EBFM. We argue here that a "balanced exploitation" approach might alleviate many of the ecological effects of fishing by avoiding intensive removal of particular components of the ecosystem, while still supporting sustainable fisheries. This concept may require reducing exploitation rates on certain target species or groups to protect vulnerable components of the ecosystem. Benefits to society could be maintained or even increased because a greater proportion of the entire suite of harvested species is used.balanced exploitation | biodiversity | sustainability | bycatch | 6-S selection

Geographically based calculations for 18,000 years ago (18 ka) and today were made to examine the potential effects on terrestrial chemical erosion of changes in lithology and hydrology on glacial‐interglacial timescales. Runoff fields were derived from general circulation model predictions of precipitation minus evaporation. Then global lithologic maps were prepared, so that empirical relationships for runoff versus bicarbonate flux for different rock types could be used to calculate global chemical erosion rates. Assuming that significant chemical erosion does not occur beneath ice sheets, we find that chemical erosion in ice‐free areas at 18 ka was only slightly greater than today. This result arises because the amount of land covered by ice sheets is roughly compensated for by exposed shelf areas and because there is little difference in global runoff. The small (∼20%) increase in the global chemical erosion rate during glacial conditions is due to exposure on the shelves of a relatively high proportion of carbonates (which weather faster than average). Data on glacial/interglacial movements of the calcite compensation depth (CCD) are inconclusive but seem to indicate little change, whereas even a 20% increase in the riverine bicarbonate flux should cause an observable deepening. If the CCD did not indeed change, then our predicted increase in the bicarbonate flux from land during glaciations would have to be accommodated by other means, such as increased carbonate productivity. About half of the observed decrease in atmospheric pCO2 at 18 ka could be explained if increased silicate chemical erosion accompanied increased total chemical erosion in ice‐free areas. Consideration of the maximum possible effect of meltwater at ice margins leads to an 80% increase in the global chemical erosion rate at 18 ka. Such an increase would lead to a larger and faster drop in atmospheric pCO2 but also to an excessive deepening of the global CCD; this scenario seems unrealistic. Our results are contrary to interpretations of a much higher silicate chemical erosion rate during glaciations based on recently published records of Quaternary marine Sr isotopic ratios. Therefore, if these records are indeed globally representative and entirely due to increased silicate chemical erosion (as opposed to changes in source areas or hydrothermal inputs), then other factors, such as a shift in the global weathering regime which we do not explicitly consider here, may be involved. Sensitivity tests show that considering spatial heterogeneities in lithology and runoff leads to lower predictions of global chemical erosion rates than what one would obtain by considering only global averages in a non‐spatially‐resolved calculation.

There is a high prevalence of wrong level surgery among spine surgeons; 1 of every 2 spine surgeons may perform a wrong level surgery during his or her career. Although all spine surgeons surveyed report using at least 1 preventive action, the following measures are highly recommended but inconsistently adopted: direct preoperative communication with the patient by the surgeon, marking of the intended site, and the use of intraoperative verification radiograph.

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