Alert on the Mediterranean sperm whale subpopulation

Giuseppe Notarbartolo di Sciara has attracted our attention to recent events concerning the Mediterranean subpopulation of sperm whales, which has been red-listed as Endangered since 2006 based on an inferred continuing decline of an already reduced population (assumed to be in the low to mid hundreds). In the past, the main cause of mortality in the Mediterranean was bycatch in pelagic driftnets, which have now been banned from the region since 2001. Driftnets continue to be deployed illegally by several Mediterranean fleets, but fishing intensity has significantly decreased because of the ban and there were hopes that the sperm whale population would be recovering.

Dead mother and calf Sperm Whale photographed off Ponza, Italy in June 2019.

Unfortunately, mortality in driftnets still occurs as shown by recent reports of multiple entanglements – a social unit of 8 whales in Algeria in May 2019 and a mother-calf pair in Italy in June 2019. Also, an unusual mortality phenomenon affecting sperm whales in Italy is being investigated by Sandro Mazzariol and colleagues. Fourteen animals were found dead over a 6-month period (24/12/2018 – 01/07/2019) between Sicily and Tuscany, with a cluster near Sicily in May. Two more were reported as stranded along the French Mediterranean coast in November 2018 and one more carcass (presumed to be a sperm whale) was found floating off Liguria in July 2019. All the carcasses were in an advanced state of decomposition, most of them calves or juveniles with stomachs empty or containing plastic debris (which was not the cause of death).

Finally, Greece is issuing extensive concessions for seismic surveys for oil & gas prospecting along the Hellenic Trench, an area that hosts the largest concentration of sperm whales in the Eastern Mediterranean (about 60 individuals) and which is designated as an Important Marine Mammal Area (IMMA). The prospect of prolonged ensonification of this important sperm whale habitat is of great concern.


Northern Gulf of California World Heritage Site Listed as ‘In Danger’

When the Islands and Protected Areas of the Gulf of California were listed by UNESCO as an area of Outstanding Universal Value in 2005, it was noted that the site contained a third of the world’s marine cetacean species, most importantly, the endemic vaquita. In early July of this year, only 14 years after inscription, it was added to the list of World Heritage Sites in Danger. The reason for this change of status is simple: the well-documented precipitous decline and imminent extinction of the vaquita. It is feared that there were no more than around 10 vaquitas left (range of 6-19) in the late summer of 2018. Since then and through the first half of 2019, illegal fisheries have ramped up. Not only has illegal totoaba fishing continued and become more violent toward efforts to remove nets (see earlier vaquita updates this year), but also since the compensation program for fishermen was terminated without a readily available alternative fishing method , fishermen have returned to gillnetting for sharks, Spanish mackerel (or sierra, Scomberomorus sierra and S. concolor), chano (Micropogonias megalops), and curvina (Cynoscion othonopterus).

 

The World Heritage Committee stresses that the listing of a site as ‘in danger’ doesn’t represent a sanction, per se. Rather, it is meant as a way to stimulate and enhance action to protect threatened sites and endangered species. Countries, in this case Mexico, are encouraged to use the designation as an opportunity to attract funding and expertise and hence strengthen protection measures. We can only hope that Mexico acts decisively and urgently to address two of the key failures in its vaquita conservation strategy: (i) effective enforcement of laws and (ii) provision of alternative livelihoods for fishermen, including access to alternative fishing gear.

April 2019 Vaquita Update

Totoaba season is winding down but gillnetting for other fish is rampant

Following the 28 March incident (Sea Shepherd report can be read here), net removal operations were temporarily suspended. The Narval did not return in April and the Farley Mowat and Sharpie worked only during the last half of April. Sea Shepherd added a third larger ship named White Holly. Crews are confident that there are no longer any active totoaba nets in the ‘zero tolerance’ area due to extensive patrolling of this and surrounding areas (see map below).

December January February March April TOTAL
Farley Mowat 41 13 6 35 3 98
Sharpie 8 26 1 35
Narval 9 10 6 25
TOTAL 41 22 24 67 4 158

However, following an announcement by the Mexican government that the program to compensate fishermen for not fishing would cease, many returned to gillnet fishing without permits. Fishermen working on the net removal vessels reported that some of those who were back on the water fishing were staying away from the zero tolerance area where the net removal effort is concentrated. However, others are actively gillnetting within the area and refuse to move when requested (see radar image and map of pangas spotted by radar).  Because these fishermen stay with their nets, the nets are not removed.  The relatively extensive ongoing illegal gillnetting represents a clear danger to the few remaining vaquitas and it impedes the deployment of acoustic monitoring devices.  Without acoustic data to guide researchers to the locations of vaquitas, planned photo-identification work has been delayed until the fishing has essentially stopped.

The map (Source: Sea Shepherd Conservation Society Internal Reports, 2019) shows the locations of active nets removed through April 2019 by the Farley Mowat, Sharpie and Narval (yellow dots for April and black dots for earlier this totoaba season).  The black line shows the area of the enhanced enforcement program which includes both the Vaquita Refuge and the exclusion zone that was recommended by CIRVA in 2017.  The slanted rectangle indicates the zero tolerance area that was recommended by CIRVA this year for nets to be removed within hours because this is a particularly high-use area for vaquitas.

An image of the radar screen on 3 May 2019 at 5:38 pm (Pacific Daylight Time).  The position of the ship is in the center of the image as a red circle. The zero tolerance area known to have the highest density of vaquitas is the slanted rectangle outlined by a dashed line. The bright dots (at least 60 visible, with 15 inside the zero tolerance area) are panga positions. Typically each panga sets at least one gillnet over 1 km long, so at a minimum there was likely at least 15 km of gillnet hanging inside the area inhabited by the last few vaquitas.

Map of positions of pangas shown on radar over a 2-week period in April 2019. Because the same panga may be recorded multiple times, the map should be interpreted as showing the general pattern of use and not the number of pangas present in the area at a given time.  The primary conclusion is that a great deal of gillnetting has continued to occur within the area of highest density of vaquitas, with no clear evidence that fishermen are avoiding that area.

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